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Solid-State Laser Spectra-Physics Quanta-Ray MOPO-HF User Manual

Optical parametric oscillator
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MOPO-HF
Quanta-Ray
Optical Parametric Oscillator
User's Manual
The Solid-State Laser Company
1335 Terra Bella Avenue
Mountain View, CA 94043
Part Number 0000-267A, Rev. C
August 2002

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Summary of Contents for Solid-State Laser Spectra-Physics Quanta-Ray MOPO-HF

  • Page 1 MOPO-HF Quanta-Ray Optical Parametric Oscillator User’s Manual The Solid-State Laser Company 1335 Terra Bella Avenue Mountain View, CA 94043 Part Number 0000-267A, Rev. C August 2002...

  • Page 3: Preface

    Preface Thank you for purchasing the Spectra-Physics Quanta-Ray MOPO-HF sys- tem. This manual contains information you need in order to safely install, align, operate, maintain, and service your MOPO-HF optical parametric oscillator. The system comprises two or three elements: the MOPO-HF head, a digital controller, and an optional Model FDO-970 frequency dou- bler (that installs inside the laser head).
  • Page 4 Quanta-Ray MOPO-HF Optical Parametric Oscillator strated for “EN 50081-2:1993 Emissions” and “EN 50082-1:1992 Immu- nity” as listed in the official Journal of the European Communities. It also meets the intent of “Directive 73/23/EEC for Low Voltage.” Class A com- pliance was demonstrated for “ Safety Requirements for EN 61010-1:1993 Electrical Equipment for Measurement, Control and Laboratory use”...

  • Page 5: Ce Environmental Specifications

    CE Environmental Specifications CE Electrical Equipment Requirements For information regarding the equipment needed to provide the electrical service listed under “Service Requirements” at the end of Chapter 3, please refer to specification Plug, Outlet and Socket Couplers for Indus- EN-309, “ trial Uses listed in the official Journal of the European Communities.

  • Page 7: Table Of Contents

    Table of Contents Preface ............. . iii CE Environmental Specifications.
  • Page 8 Quanta-Ray MOPO-HF Optical Parametric Oscillator Chapter 3: Description ..........3-1 OPO Theory of Operation .
  • Page 9 Table of Contents Chapter 6: Operation ........... 6-1 MOPO-HF/FDO Dos and Don’ts .
  • Page 10 Quanta-Ray MOPO-HF Optical Parametric Oscillator Return of the Instrument for Repair ..........9-2 Service Centers .
  • Page 11 Table of Contents List of Figures Figure 1-1: The Quanta-Ray MOPO-HF System ......... 1-1 Figure 1-2: The Quanta-Ray MOPO-HF Digital Controller .
  • Page 12 Quanta-Ray MOPO-HF Optical Parametric Oscillator Figure 5-20: Orientation of the BBO Crystal ..........5-27 Figure 5-21: Horizontal displacement of reference beam from PH pinhole.

  • Page 13: Warning Conventions

    Warning Conventions The following warnings are used throughout this manual to draw your attention to situations or procedures that require extra attention. They warn of hazards to your health, damage to equipment, sensitive procedures, and exceptional circumstances. All messages are set apart by a thin line above and below the text as shown here.

  • Page 15: Standard Units

    Standard Units The following units, abbreviations, and prefixes are used in this Spectra- Physics manual: Quantity Unit Abbreviation mass kilogram length meter time second frequency hertz force newton energy joule power watt electric current ampere electric charge coulomb electric potential volt Ω...

  • Page 17: Unpacking And Inspection

    Unpacking and Inspection Unpacking Your MOPO-HF Your MOPO-HF system was packed with great care, and its container was inspected prior to shipment—it left Spectra-Physics in good condition. Upon receiving your system, immediately inspect the outside of the ship- ping containers. If there is any major damage (holes in the containers, crushing, etc.), insist that a representative of the carrier be present when you unpack the contents.

  • Page 19: Chapter 1 Introduction

    Chapter 1 Introduction The Quanta-Ray MOPO-HF Optical Parametric Oscillator Overview Figure 1-1: The Quanta-Ray MOPO-HF System The principal of operation for an optical parametric oscillator (OPO) is quite different from that for a laser system. Whereas a laser derives its gain from the spontaneous and stimulated emission generated by atomic transi- tions, an OPO’s gain is derived from a nonlinear frequency conversion pro- cess.

  • Page 20: The Mopo Opo

    Quanta-Ray MOPO-HF Optical Parametric Oscillator ies of combustion processes, atmospheric chemistry and other gas-phase spectroscopies. The tuning and energy range of the MOPO-HF have not been compro- mised in the effort to narrow the linewidth. Tuning with a single optics set still exceeds 450–1700 nm and some systems have output energy levels in excess of 75 mJ.

  • Page 21: The Advantage Of The Mopo-Hf

    Introduction The Advantage of the MOPO-HF • Narrow linewidth • Highest damage threshold optics in the industry • Microprocessor-based controller • A user-friendly, menu-driven graphical interface • Optional IEEE-488 parallel and RS232 serial interfaces for remote control Patents The Quanta-Ray MOPO-HF series is manufactured under one or more of the following patents: 5,053,641 5,047,668...
  • Page 22 Quanta-Ray MOPO-HF Optical Parametric Oscillator...

  • Page 23: Chapter 2: Laser Safety

    Chapter 2 Laser Safety The Spectra-Physics Quanta-Ray MOPO-HF Optical Parametric Oscil- Danger! lator and its pulsed Nd:YAG pump laser are a Class IV-High Power Laser Radiation Laser Products whose beams are, by definition, safety and fire hazards. Take precautions to prevent accidental exposure to both direct and reflected beams.

  • Page 24: Figure 2-1: These Standard Safety Warning Labels Would Be Appropriate For Use As Entry Warning Signs (En60825-1, Ansi 4.3.10.1)

    Quanta-Ray MOPO-HF Optical Parametric Oscillator • Establish a controlled access area for laser operation. Limit access to those trained in the principles of laser safety. • Set up experiments so the laser beam is either above or below eye level. •...

  • Page 25: Focused Back-Reflection Safety

    Laser Safety Follow the instructions contained in this manual to ensure proper installa- tion and safe operation of your laser. Focused Back-Reflection Safety Focused back-reflections of even a small percentage of the output energy of series laser can destroy its optical components. To illustrate, con- Pro- sider an uncoated convex lens, which reflects about 4% of the energy inci- dent on each of its surfaces.

  • Page 26: Safety Interlocks

    Quanta-Ray MOPO-HF Optical Parametric Oscillator 6. Verify, when the cover interlock on the pump laser is defeated, the defeat mechanism is clearly visible and prevents installation of the cover until disengaged. Safety Interlocks Because the MOPO-HF is not a laser and therefore cannot generate output energy without being pumped by a laser, it requires no safety interlocks.

  • Page 27: Ce/Cdrh Radiation Control Drawing

    Laser Safety CE/CDRH Radiation Control Drawing (Labels shown on next page) Input Port MOPO-HF, Input End View MOPO-HF, Output End View Quanta-Ray VISIBLE AND/OR INVISIBLE* LASER RADIATION AVOID EYE OR SKIN EXPOSURE TO DIRECT OR VISIBLE INVISIBLE* VISIBLE INVISIBLE* LASER RADIATION WHEN SCATTERED RADIATION...

  • Page 28: Ce/Cdrh Warning Labels

    Quanta-Ray MOPO-HF Optical Parametric Oscillator CE/CDRH Warning Labels D A N G E R D A N G E R VISIBLE INVISIBLE* LASER RADIATION WHEN VISIBLE V I S I B L E A N D I N V I S I B L E * OPEN.

  • Page 29: Label Translations

    Laser Safety Label Translations For safety, the following translations are provided for non-English speak- ing personnel. The number in parenthesis in the first column corresponds to the label number listed on the previous page. Label # French German Spanish Dutch Aperture Ouverture Laser - Austritt von sichtbarer...
  • Page 30 Quanta-Ray MOPO-HF Optical Parametric Oscillator Label # French German Spanish Dutch CE Dan- Rayonnement Laser Austritt von sichtbarer Al abrir y retirar el Zichtbare en neit ger Label Visible et Invisible en un unsichtbarer dispositivo de segu- zichtbare laserstral- Cas D’Ouverture et Laserstrahlung wenn ridad exist radiación ing wanneer geopend...

  • Page 31: Ce Declaration Of Conformity

    Laser Safety CE Declaration of Conformity Spectra-Physics, Inc. Scientific and Industrial Systems 1330 Terra Bella Avenue P.O. Box 7013 Mountain View, CA. 94039-7013 United States of America declare under sole responsibility that the: Quanta-Ray MOPO-HF series Pulsed Optical Parametric Oscillators with digital controller, manufactured after December 31, 1995 meets the intent of “Directive for Electromagnetic Compatibility.”...
  • Page 32 Quanta-Ray MOPO-HF Optical Parametric Oscillator CE Declaration of Conformity Spectra-Physics, Inc. Scientific and Industrial Systems 1330 Terra Bella Avenue P.O. Box 7013 Mountain View, CA. 94039-7013 United States of America declare under sole responsibility that the Quanta-Ray MOPO-HF series Pulsed Optical Parametric Oscillators with digital controller, meets the intent of “Directive , the Low Voltage directive.”...

  • Page 33: Sources For Additional Information

    Laser Safety Sources for Additional Information The following are some sources for additional information on laser safety standards, safety equipment, and training. Laser Safety Standards Safe Use of Lasers (Z136.1: 1993) American National Standards Institute ( ANSI 11 West 42 Street New York, NY 10036 Tel: (212) 642-4900...

  • Page 34: Equipment And Training

    Quanta-Ray MOPO-HF Optical Parametric Oscillator Equipment and Training Laser Safety Guide Laser Institute of America 12424 Research Parkway, Suite 125 Orlando, FL 32826 Tel: (407) 380-1553 Laser Focus World Buyer's Guide Laser Focus World Penwell Publishing 10 Tara Blvd., 5 Floor Nashua, NH 03062 Tel: (603) 891-0123...

  • Page 35: Chapter 3: Description

    Chapter 3 Description OPO Theory of Operation The gain of an optical parametric oscillator (OPO) system is derived from the nonlinear interaction between an intense optical wave and a crystal hav- ing a large nonlinear polarizability coefficient. Beta Barium Borate (BBO) is a negative uniaxial crystal with intrinsic birefringence properties that are used to achieve critical phase matching required by this process.

  • Page 36: Bbo Enables Opo Commercialization

    Quanta-Ray MOPO-HF Optical Parametric Oscillator θ Variable ω 450 – 690 nm (Signal) ω 355 nm ω 730 – 1700 nm (Idler) Pump Beam Figure 3-2: Parametric Amplification to Generate Tunable Output from 450 nm to Beyond 1700 nm. The output of an OPO is very similar to that of a laser. The signal and idler beams exhibit strong coherence, are highly monochromatic, and have a spectrum consisting of one or more longitudinal modes.

  • Page 37: Mopo Operation

    Description • High damage threshold to sustain the intense pump fluence required for the nonlinear interaction. • Low absorption over the entire tuning range. • Ability to be fabricated in useful sizes. • No significant degradation with time. The only material fitting these criteria is BBO, and it has only been in recent years that high quality BBO crystals have been available in useful sizes necessary for the commercialization of OPO devices.

  • Page 38: Figure 3-4: The Mopo-Hf Master Oscillator Uses A Grazing Incidence Geometry To Produce

    Quanta-Ray MOPO-HF Optical Parametric Oscillator When a pump pulse enters the BBO crystal in the master oscillator, quan- tum noise fluctuations result in the parametric generation of signal and idler photons. These photons have an intrinsic gain bandwidth that is deter- mined by the dispersion of the BBO crystal.

  • Page 39: Power Oscillator

    Description Undepleted Depleted Parametric Pump Pulse Pump Pulse Output Pulse ∆t = 10 – 12 ns ∆t = 3 – 4 ns time time time Figure 3-5: Pump pulse depletion and resulting parametric output pulse. Power Oscillator The key feature of the power oscillator is the use of a geometrically unsta- ble resonator design, originally patented by Quanta-Ray for use in Nd:YAG lasers.

  • Page 40: The Seeding Process

    Quanta-Ray MOPO-HF Optical Parametric Oscillator Pump In Pump Out Crystal Output Broadband Broadband Compensator Coupler Dichroic Signal and High Reflector Idler Output Idler Xtal Seed Radiation Signal 355 nm Residual Dichroics Broadband Idler Dichroic Figure 3-7: Power oscillator cavity geometry. Illustration shows separation of signal and idler output beams with broadband dichroic mirrors.

  • Page 41: Dichroic Beam Separation

    Description Optimal seeding requires that the seed pulse arrive in the crystal before the pump pulse. This requirement is satisfied by a suitable optical delay line for the pump beam. The seeding process is also enhanced when the oscilla- tor is running near-threshold. This is realized in the power oscillator with an appropriate choice of pump energy, and spot size the BBO crystal.

  • Page 42: Figure 3-9: Collinear (A) And Noncollinear (B) Phase Matching

    Quanta-Ray MOPO-HF Optical Parametric Oscillator OPOs as commercial devices. As discussed previously, gain in an OPO is derived from a nonlinear optical phenomenon which results in the decom- position of a pump photon into a signal and idler photon. Unlike a laser, this process does not require a real atomic or molecular transition.

  • Page 43: Automated Control Electronics

    Description divergent idler to compensate for the angular divergence of the pump source. If, on the other hand, we had a diverging pump source and colli- mated signal beam, we would see a converging idler beam. To assist in linewidth reduction, the MOPO-HF master oscillator uses non- collinear phase matching.

  • Page 44: Mopo-Hf Specifications

    Quanta-Ray MOPO-HF Optical Parametric Oscillator MOPO-HF Specifications Table 3-1: MOPO-HF Output Characteristics Polarization Horizontal >97% 5 mm Beam diameter (typical) Round ±20% Beam shape (typical) <1 mrad Beam divergence <200 µrad Pointing stability Pulse width (typical) 2 ns less than pump Resettability <1 x linewidth Electronic readout accuracy (typical)

  • Page 45: Service Requirements

    Description Service Requirements Electrical service: 115/230 V, 5/3 A, 50/60 Hz single phase Mechanical Specifications Size: See Outline Drawings Weight: MOPO-HF 84 kg (185 lb) Digital controller 10 kg (22 lb) Environmental Specifications The environmental conditions under which the MOPO-HF system will function are listed below: Indoor use Altitude:...

  • Page 46: Outline Drawings

    Quanta-Ray MOPO-HF Optical Parametric Oscillator Outline Drawings 46.30 1176,0 Quanta-Ray 32.00 6.59 7.34 167,4 812,8 186,4 Side View 2.00 26.55 50,8 674,4 15.31 8.72 10.73 4.18 5.10 338,9 221,5 272,5 106,2 129,5 11.11 282,2 7.12 7.12 180,8 180,8 2.27 22.00 558,8 57,7 Input End View...

  • Page 47: Controls, Indicators And Connections

    Chapter 4 Controls, Indicators and Connections Introduction This section defines the user controls, indicators and connections of the MOPO-HF system. It is divided into two sections: the MOPO-HF head and the MOPO-HF control module. Figure 4-1 shows the relative position of the various components in the MOPO-HF.

  • Page 48: External Controls

    Quanta-Ray MOPO-HF Optical Parametric Oscillator External Controls Shutter—there is none. Because the MOPO-HF is not a laser, it does not have a shutter. When you need to block the beam temporarily, set the pump laser to Q-SWITCH OFF Cover clamping screws (4)—hold the cover securely in place. One screw is located on each corner of the cover.
  • Page 49 Controls, Indicators and Connections MO Telescope—is made up of the (described below) MO-PL MO-NL and is used to set the diameter size of the beam. —(master oscillator positive lens) is the input end of the MO tele- MO-PL scope (see above). It is mounted on a spring-loaded slide, and a micrometer provides fine adjustment for setting the separation between the two lenses.
  • Page 50 Quanta-Ray MOPO-HF Optical Parametric Oscillator —(master oscillator high reflector) reflects the beam back MO-BBHR through , the crystal, and to the grating. The mount is fas- MO-TM MO-TM tened to the base plate by two screws, and the mount is slotted so it can be moved forward and backward.
  • Page 51 Controls, Indicators and Connections —(beam splitter) directs part of the beam to the master oscillator photo detector, which monitors master oscillator output. Two screws fasten the mount to the base plate. —(turning prism) directs the beam from and on to the seed S-TP S-TP telescope (see below).
  • Page 52 Quanta-Ray MOPO-HF Optical Parametric Oscillator Loosen to rotate the mirror, turn the cams to release the mirror (you may have to actually remove one of the cams in order to remove the optic). The mount is spring-loaded against 3 balls for repeatable seating. There are ver- tical (upper) and horizontal (lower) alignment knobs for directing the beam.
  • Page 53 Controls, Indicators and Connections —(power oscillator turning mirror) provides adjustment to align PO-TM the incoming beam from and direct it to . The mount is fas- PO-TM PO-TM tened to the base plate by two screws, and the mount is slotted so it can be moved forward and backward.

  • Page 54: Indicators

    Quanta-Ray MOPO-HF Optical Parametric Oscillator with an Allen ball driver and removing the lens with the retaining ring. The lens is spring-loaded against 3 balls for repeatable seating. There are no vertical or horizontal adjustments for directing the beam. —(Macor ceramic aperture) reduces the diameter of the beam from the so the beam will fit through the clear aperture of the power oscillator PO-NL BBO crystal.

  • Page 55: The Mopo-Hf Digital Controller

    Controls, Indicators and Connections Quanta-Ray VISIBLE INVISIBLE* LASER RADIATION WHEN OPEN. AVOID SKIN OR EYE EXPOSURE TO DIRECT OR SCATTERED RADIATION. *SEE MANUAL 0452-0150 Optional FDO Autotrack Sine-Drive Connector Connector Connector Figure 4-2: MOPO-HF Connectors, Right Side View The MOPO-HF Digital Controller The digital controller contains the CPU that controls the various circuits required to select wavelengths.

  • Page 56: Rear Panel

    Quanta-Ray MOPO-HF Optical Parametric Oscillator change parameters. Help menus and instructions are shown from time to time to provide assistance. To show which function or item is selected (prior to making it active), the button or associated window is highlighted with a box. To indicate which menu or function is active, it is shown in reverse video.
  • Page 57 Controls, Indicators and Connections Voltage selector—provides selection between 115 and 220 Vac. Verify this switch is set to the proper position before turning on your Warning! system for the first time. If not properly set, damage not covered by your warranty may occur to the controller and to various other voltage-sensi- tive components in the MOPO-HF.
  • Page 58 Quanta-Ray MOPO-HF Optical Parametric Oscillator 4-12...

  • Page 59: Chapter 5: Installation And Alignment

    Chapter 5 Installation and Alignment The following installation procedure is provided for reference only; it is not intended as a guide to the initial installation and set-up of your MOPO-HF. Please call your service representative to arrange an installation appoint- ment, which is part of your purchase agreement.

  • Page 60: Initial Setup

    Quanta-Ray MOPO-HF Optical Parametric Oscillator • Right-angle turning prism assembly The assembly should include the necessary hardware to place the cen- ter of the optic approximately 3.5 in. off the base plate. See Figure 5-1 (e.g., Newport SP-2, and VPH-2). Mirror Mount 2"...
  • Page 61 Installation and Alignment Set up the PRO-Series YAG laser in accordance to its user’s manual. Note This should be done by a qualified individual only (i.e., someone who has received appropriate training) 355 nm MOPO-HF PRO-Series Laser 1064/532 nm Residual Beam Beam Dump Figure 5-2: Typical Table Layout for a PRO-Series Pump Laser and the MOPO-HF...
  • Page 62 Quanta-Ray MOPO-HF Optical Parametric Oscillator b. Verify both the 2 and 3 harmonic crystals in the harmonic gen- erator (HG) are in the beam path. The 2 harmonic crystal arm should be in the “I” position for type I phase matching, or the “II” position for type II phase matching. The 3 harmonic crystal should be in the “T”...

  • Page 63: Figure 5-3: The Mopo-Hf Beam Path And Optical Layout

    Installation and Alignment PO-TM PO-TM PO-TM PO-PL PO-NL PO-TM PO-TM PO-BBO COMP S-TP Idler Beam Out S-NL S-PL PO-TM PO-TM Signal Beam Out BBHR MO-PD MO-TM MO-TM MO-BBHR Grating UV-BS UV–355 nm Tuning Mirror S-TP Pump Beam MO-TM MO-TM PO-PD MO-PL MO-NL MO-TM Beam Splitters...

  • Page 64: Electronics And Controller Setup

    Quanta-Ray MOPO-HF Optical Parametric Oscillator Verifying BeamLok Beam-pointing Sensor Alignment 13. Access the BeamLok Monitor menu (refer to the PRO-Series User’s Manual) and verify BeamLok is off. This minimizes adjustment time when BeamLok is again engaged at the conclusion of the alignment procedure. 14.

  • Page 65: Alignment

    Installation and Alignment b. Select M-OSC (F The border around the softkey highlights when it is selected. c. Use the up/down keys to change the lower menu item of the key to choices are: TABLE ( TRACK TABLE) d. Activate by holding the key in until it beeps.

  • Page 66: Figure 5-5: Unpolarized Light From A Hene Laser Shown Entering A Birefringent Crystal

    Quanta-Ray MOPO-HF Optical Parametric Oscillator without misaligning the beam by placing a sheet polarizer in the beam path without misaligning the beam (Step 3). R-TM Power Oscillator MO-BBHR Reference Beam: (removed) HeNe Laser Master Oscillator Grating MO-TM MO-TM R-TM Tuning Mirror Installation Aperture Figure 5-4: Reference beam alignment for the master oscillator.

  • Page 67: Figure 5-6: Horizontally Polarized Light Passing Through A Birefringent Crystal, Such As Bbo

    Installation and Alignment Transmission Axis (Oriented to pass horizontally polarized light) Optic Axis Unpolarized Horizontal HeNe Laser o-ray Type I BBO Crystal Sheet Polarizer Figure 5-6: Horizontally polarized light passing through a birefringent crystal, such as BBO. 5. Establish alignment of HeNe beam to reference pinholes a.
  • Page 68 Quanta-Ray MOPO-HF Optical Parametric Oscillator This allows internal controller operation during the following steps without the need to run the PRO-Series laser. To operate the MO and PO monitors, the trigger must be changed back to the out- Q-SWITCH put port, which will be done at a later step. 10.

  • Page 69: Figure 5-7: Tuning Mirror Adjustments

    Installation and Alignment The retroreflection may be viewed on the flat side of pinhole carefully rocking the tuning mirror plate that is attached to the sine bar mechanism. Note that the displacement is in the horizontal plane. If the retroreflection is not overlapped with , perform one of the following: a.

  • Page 70: Master Oscillator Overlap Procedure

    Quanta-Ray MOPO-HF Optical Parametric Oscillator 20. Place the aperture back into its mount. Orient it so that the flat side is facing the BBO crystal. 21. Place in its “alignment” position on the left-hand side of the MO-BBHR grating/tuning mirror pair (Figure 5-9). The mount should be oriented so that the front surface of the optic faces the .
  • Page 71 Installation and Alignment 2. Choose a beam splitter from the table below that will yield transmitted pulse energies in the range 65–75 mJ (values are given in% Transmis- sion). 0451-1170 0451-6440 0449-1100 0451-0670 0449-1110 The formula for calculating transmitted energy is: transmitted energy = (pump energy) x (% transmission of beam splitter)/100.

  • Page 72: Figure 5-8: Placement Of Pick-Off Prism Assembly For Master Oscillator Pump Energy

    Quanta-Ray MOPO-HF Optical Parametric Oscillator Power Oscillator To PO Master Oscillator MO-TM Pick-off Pump in Prism (355 nm) UVBS MO-TM To Power Meter Figure 5-8: Placement of pick-off prism assembly for master oscillator pump energy measurement f. If the energy is not in the desired range of 60–75 mJ, choose another beam splitter (see Step 2 above), install it, then verify the beam is still centered in .
  • Page 73 Installation and Alignment is used to limit the size of the beam. This is useful in the next alignment step. h. Place the negative lens mount back in its appropriate loca- MO-NL tion in the pump beam line. The beam should be in the approxi- mate center of the lens.

  • Page 74: Figure 5-10: Placement Of Pick-Off Prism For Pump Collimation

    Quanta-Ray MOPO-HF Optical Parametric Oscillator R-TM Power Oscillator To PO MO-BBHR Reference Beam: (removed) HeNe Laser Master Oscillator MO-BBHR (alignment location) R-TM Pump in (Long Pulse mode of Installation operation) Aperture Figure 5-9: Placement of for pump beam alignment. MO-BBHR Power Oscillator Master Oscillator Pick-off...
  • Page 75 Installation and Alignment Warning! If the beam is converging it can cause damage to the optical compo- nents. Therefore, be sure the beam is diverging initially. It LONG PULSE should be approximately 1 mm larger at the beam dump than at the neg- ative lens location.

  • Page 76: Figure 5-11: Overlap Location Of Hene Reference And Pump Beams

    Quanta-Ray MOPO-HF Optical Parametric Oscillator Power Oscillator To PO MO-BBHR (removed) Master Oscillator Grating MO-TM MO-TM Reference MO-BBHR Beam In Tuning Pump in Mirror (Long Pulse mode of operation) MO-TM MO-TM Alignment Card Figure 5-11: Overlap Location of HeNe Reference and Pump Beams b.
  • Page 77 Installation and Alignment g. Adjust the horizontal and vertical so the pump and HeNe MO-TM beams are overlapped on the alignment card. This step ensures that both beams are in the same horizontal plane (i.e., identical dis- placements from the base plate). Note At this point the beams will not be overlapped in front of the crystal.

  • Page 78: Attaining Oscillation In The Master Oscillator

    Quanta-Ray MOPO-HF Optical Parametric Oscillator Pinhole Horizontal Axis Pump beam retro-reflection from MO-TM overlapped on the pinhole Figure 5-13: Retroreflection from MO-TM Attaining Oscillation in the Master Oscillator 1. Change to mode. LONG PULSE 2. Place the pick-off prism assembly in a position to intercept the output beam from the MO (Figure 5-14).
  • Page 79 Installation and Alignment a. Bend the short side of a business card so the bent portion is approximately 10 mm wide. b. To see if it works, hang the card over the front side of the MO-BBHR optic (Figure 5-15). Business Card Figure 5-15: A business card folded and hung over the...

  • Page 80: Optimize The Master Oscillator

    Quanta-Ray MOPO-HF Optical Parametric Oscillator a. Change to mode. LONG PULSE b. Turn off the seeder. c. Change to mode. Q-SWITCH d. Manually adjust the crystal until oscillation is achieved. Change to mode. LONG PULSE Turn on the seeder. g. Change to mode.
  • Page 81 Installation and Alignment 3. Rotate the sine bar gear wheel manually to optimize output power. If the peak output power is lower than that noted in Step 2, repeat these last two steps, this time turning the control counter-clock- MO-BBHR wise.

  • Page 82: Linewidth Measurement

    Quanta-Ray MOPO-HF Optical Parametric Oscillator For optimal operation, the energies at the extremes of the tuning range Note should be 1–2 mJ. Beware of multiple oscillations near 690 nm. These additional oscilla- Note tions are at wavelengths that are shorter than the primary order. The cor- rect order may be identified as being the last one observed as the crystal is tuned to the red.

  • Page 83: Establish Reference Beam For Power Oscillator

    Installation and Alignment Peak-to-Peak Displacement (Free Spectral Range) Full Width At Half Maximum (FWHM) Figure 5-18: FWHM Ratio of a particular fringe to the fringe spacing. Establish Reference Beam for Power Oscillator If the PO has been previously aligned, establish the reference beam Note according to Method A below.
  • Page 84 Quanta-Ray MOPO-HF Optical Parametric Oscillator b. Place alignment mirror approximately 1 foot (30 cm) in front R-TM The space between the MOPO-HF and the routing mirror leaves room for the placement of a power meter. c. Place an aperture assembly on the dowel pins at d.

  • Page 85: Figure 5-20: Orientation Of The Bbo Crystal

    Installation and Alignment Comp HeNe PO-BBHR PO-TM PO-TM Figure 5-20: Orientation of the BBO Crystal a. Loosen the compensator holder. b. Rotate the compensator so that the retroreflection closest to the optic is on the left side of c. Verify the compensator is centered in the beam. Make adjustments if necessary.
  • Page 86 Quanta-Ray MOPO-HF Optical Parametric Oscillator g. Adjust to center the beam on h. Iterate the last two steps until the beam is centered through the two pinholes. 4. Reverse the pinhole in so the flat side faces the BBO crystal. This allows retroreflections from the oscillator optics to be seen during the following steps.
  • Page 87 Installation and Alignment Improved accuracy is usually attained by directing the beam back into Note the laser. When a correct alignment is achieved, interference fringes should be noticed around the outside edge of the HeNe output aperture. c. Rotate the so the HeNe beam at goes onto (or very close to) the pinhole.

  • Page 88: Power Oscillator Overlap Procedure

    Quanta-Ray MOPO-HF Optical Parametric Oscillator 18. Observe the retroreflections from the back surface of the PO-BBHR , and loosen the optic and rotate it so the retroreflections are in a horizontal line parallel to the base plate. 19. Install the in its standard location on the base plate.
  • Page 89 Installation and Alignment overlap the pump with a horizontally polarized HeNe beam. Because the HeNe beam passes through the crystal twice, it will follow the same path the pump does on the output side of the BBO crystal. This enables the polarization of the pump and reference beams to be orthogonal.

  • Page 90: Figure 5-23: Overlap Of Hene Reference And Pump Beam For Power Oscillator

    Quanta-Ray MOPO-HF Optical Parametric Oscillator 2. Adjust the sheet polarizer so the reference beam is horizontally polar- ized. Verify the reference beam is still aligned , and 3. The pump beam should be roughly centered in . Figure 5-23. If PO-TM it is not, adjust the position of the mirror mount as necessary.

  • Page 91: Figure 5-24: Power Oscillator Pick-Off Prism Placement

    Installation and Alignment d. Iterate Steps b and c until the “apertured” beam is centered through the pinholes at e. Remove Verify the beam is not clipping on PO-RM 10. Overlap pump and HeNe beams: a. Remove PO-TM b. Place a pick off prism on the base plate where was located.
  • Page 92 Quanta-Ray MOPO-HF Optical Parametric Oscillator h. Reiterate Steps f and g until the beams are overlapped in the two locations. If it is difficult to attain overlap by iterating these adjustments (e.g. run Note out of travel on one of the mounts), perform the following steps. i.
  • Page 93 Installation and Alignment For example, a 1.2 x telescope which consists of a + 240 mm and –200 mm focal length lenses should be displaced by approximately 40 mm. 16. Make the necessary horizontal and vertical adjustments of the positive lens mount position re-overlap the pump and HeNe beams on the busi- ness card at the diagnostic output port.

  • Page 94: Attaining Oscillation In The Power Oscillator

    Quanta-Ray MOPO-HF Optical Parametric Oscillator iii. Mark the location of the beam. iv. Adjust the positive lens mount position in the direction neces- sary to attain the desired degree of collimation (see Note below). If the beam divergence is too great, move the positive lens away from Note the negative lens.
  • Page 95 Installation and Alignment a. Access the screen and enter 500 nm in the menu. OPERATE GOTO b. Press the button down and hold it until a beep is heard. GOTO 4. Verify a power meter head is in the output signal beam path. This will be used to measure the signal output power, as well as to judge overall stability and seeding optimization.

  • Page 96: Seeding The Power Oscillator

    Quanta-Ray MOPO-HF Optical Parametric Oscillator 10. Use this procedure to achieve collimation of the signal output beam. a. Set to mode. LONG PULSE b. Remove from signal beam output path. R-TM c. Place power meter or a beam dump 2–3 m from signal beam out- put port.
  • Page 97 Installation and Alignment Seed Beam Alignment (coarse alignment) 1. Change to mode. LONG PULSE 2. Place back onto the base plate. S-TP 3. Verify the top half of the seed telescope assembly has been removed. 4. Place a beam block in the pump beam path at a location before .

  • Page 98: Optimizing Seed Beam Alignment

    Quanta-Ray MOPO-HF Optical Parametric Oscillator a. Access the monitor menu on the MOPO-HF controller. b. Note the signal levels on the MO monitor. c. Maximize the signal level on the MO monitor by adjusting its posi- tion so that the Fresnel reflections from are centered on the detector.
  • Page 99 Installation and Alignment cavity. Since the telescope expands the seed beam up to 6 times its ini- tial size, the light will overfill the clear aperture of the crystal compen- sator. Thus the expanded seed light will have a rectangular appearance. Initial collimation is attained by making the size of the rectangular “cone”...

  • Page 100: Part Ii: Seed Beam Alignment Using An Optical Parametric Amplifier (Opa)

    Quanta-Ray MOPO-HF Optical Parametric Oscillator b. Tune the MO wavelength 5–10 nm around 500 nm to find the transmission peak for the coating. The peak may be veri- PO-BBHR fied by observing maximum brightness of the seed light on The transmission peak is usually in the 500–505 nm region. The following procedure may be used to assess location of this peak.

  • Page 101: Part Iii. Conversion To Unseeded Opo

    Installation and Alignment 6. Wait several minutes for the MO output power to stabilize. 7. Adjust the PO crystal until amplification is observed: a. Access the crystal device menu. b. Press the softkey to activate it. PO XTAL c. Access the table writing options softkey. Toggle through the menu options until is obtained.
  • Page 102 Quanta-Ray MOPO-HF Optical Parametric Oscillator 8. Block the seed beam from the 9. Change to mode. Unseeded oscillation should resume. Q-SWITCH 10. Check to see if the mount is clipping either the primary output beam or the Fresnel reflections directed onto .

  • Page 103: Optimizing Mopo Operation

    Installation and Alignment Optimizing MOPO Operation Fine Tuning MOPO Collimation Achieving well collimated pump, signal and idler beams is important to achieve best linewidth and beam propagation characteristics. Use this procedure only if the signal and idler mode characteristics are Note not suitable.
  • Page 104 Quanta-Ray MOPO-HF Optical Parametric Oscillator 5-46...

  • Page 105: Chapter 6: Operation

    Chapter 6 Operation MOPO-HF/FDO Dos and Don’ts Your system must be set up on an optical table to ensure mechanical stabil- ity, and steps must be take to ensure there are no air currents (e.g., heating and/or air conditioning registers or ducts directly over the table) and that there are no rapid changes in air temperature while the unit is running.

  • Page 106: Dos

    Quanta-Ray MOPO-HF Optical Parametric Oscillator • Do not run the PRO-Series laser if the Seeder is off or is performing poorly. Linewidth performance will degrade and parasitic oscillations may result. In addition, damage to the broadband dichroics may occur. • Do not use the PRO-Series laser option when running SINGLE SHOT...

  • Page 107: Hints, Tips & Reminders For Daily Operation

    Operation Number of Shots as Function of Rep. Rate and Duration 1 Day (8hrs) 1 Week (40 hrs) 1 Month (160 hrs) 10 Hz 288,000 1.44 million 5.76 million 30 Hz 864,000 4.32 million 17.28 million 50 Hz 1.44 million 7.2 million 28.8 million •...

  • Page 108: General Operation Hints

    Quanta-Ray MOPO-HF Optical Parametric Oscillator When the ratio is small, the error signal decreases. In this case, locking becomes more difficult. Threshold values are used by the system to assist in discriminating between local maxima and the absolute peak associated with a fully seeded system.

  • Page 109: Daily Shut Down Procedure

    Operation 9. If the is installed and you are frequency doubling, change the , then use the Monitor1 menu to verify MOPO-HF FDO MODE output is within 10% of the value it had at installation. 10. If you need to move the out of the beam path, simply flip it around.

  • Page 110: The "Sss" (Select, Scroll, Set) Procedure

    Quanta-Ray MOPO-HF Optical Parametric Oscillator previously selected. These keys are referred to throughout this manual as function keys 1 through 5 ( 1 – 5 Use the two up/down arrow keys (up/down buttons) to the right of the dis- play either to change the numerical value inside a highlighted box on the display or to scroll through the various selections.

  • Page 111: Setting Numeric Values

    Operation Setting Numeric Values procedure is not used with the Setup1 menu to set numeric values. Instead, press the function button whose value you want to change, then press that same button repeatedly to select the digit you wish to change (an underscore symbol moves under the digits) and use the up/down buttons to change the numerical value of that digit.

  • Page 112: A Brief Description

    Quanta-Ray MOPO-HF Optical Parametric Oscillator A Brief Description The following is a short description of each menu. A complete description of each follows later in this chapter. The Operate1 Menu (page 6-11): is displayed when the system is first turned on and any time the button is pressed.
  • Page 113 Operation Setting Large Letters Small Letters SIGNAL Signal Idler IDLER Idler Signal Signal • the display mode to (6 digits) or (7 digits) NORM MICRO • the displayed wavelength units: either • the master oscillator display gain: 1, 2, 4, 8, 16x •...
  • Page 114 Quanta-Ray MOPO-HF Optical Parametric Oscillator • the starting and end wavelength for a SCAN • the system for a inuous scan at a user-defined rate or for an CONT incremental scan with dwell points at user-defined pre-set wavelengths and a preset number of given at each dwell.

  • Page 115: Figure 6-2: The Operate1 Menu

    Operation The Monitor1 Menu (page 6-23): is displayed whenever the MONITOR button is pressed. M_OSC P_OSC 500000 OPERATE1 REMOTE 1428 7350 MONITOR1 START MOPO SCAN TABLE It displays: • the master oscillator power, numerically and graphically, and error tracking • the power oscillator power, numerically and graphically, and error tracking •...
  • Page 116 Quanta-Ray MOPO-HF Optical Parametric Oscillator The Display: When has been selected in the Operate2 menu, the large number in SIGNAL the upper right-hand box is the signal wavelength and the idler is the small number. If was selected, these numbers are reversed. If IDLER selected, the large number is the MOPO-HF FDO doubled wavelength and the small one is the signal.

  • Page 117: The Operate2 Menu

    Operation The Operate2 Menu Select OPERATE2 menu Current MOPO or FDO output OPERATE 500.000 OPERATE2 SETUP1 SCAN 1220.814nm MONITOR1 SETUP MODE MODE UNITS M-OSC P-OSC SIGNAL NORM MONITOR Set display to Set MOPO mode Set MOPO units Set MO Set PO SIGNAL, IDLER, to NORM to nm or cm...

  • Page 118: The Service1 Menu

    Quanta-Ray MOPO-HF Optical Parametric Oscillator tions are useful in most cases when simply monitoring system output. This feature is saved along with all other data when using the function SAVE from the Operate1 menu. The Function Keys: —allows you to select the wavelength dis- : MODE: SIGNAL/IDLER/FDO play format.

  • Page 119: The Setup1 Menu

    Operation This menu allow you to identify your software revision number, which is required when determining whether or not to update the firmware and whenever you talk to your Spectra-Physics service representative. The Display: Displayed is the selected operating mode ( ), the output wavelength OPMOD ), the master and power oscillator power (...
  • Page 120 Quanta-Ray MOPO-HF Optical Parametric Oscillator be no dwell during the scan). Just below is the scan rate in nm/s. CONT When is set to “1” or greater, is displayed over to indicate SHOTS INCR the system is set for an incremental scan. An incremental scan starts at the beginning wavelength, then moves by the nm increments (.xxx nm) shown under The scan stops (dwells) at each increment and the system...

  • Page 121: The Setup2 Menu

    Operation to select it, then press it repeatedly to select the digit you wish to change and use the up/down buttons to set its numerical value. Press the button again to move to the next digit, etc. .—indicates the system is set for an incremental scan. The incre- : INCR ment scan size between dwells is displayed in nanometers below INCR...
  • Page 122 Quanta-Ray MOPO-HF Optical Parametric Oscillator From this menu, you can also set a base and peak value for the PO-PD (power oscillator pyrodetector) by selecting . Refer to the BASE PEAK “Threshold Table-Writing Procedure” on page 6-31, for a description of how this works.
  • Page 123 Operation : (Lagrange) performs a curve-fitting algorithm over a large pre- LAGRNG scribed scan range (set up under the Setup1 menu). The begin- ning scan wavelength has to be less than the ending wavelength, and, with regard to the MOPO-HF FDO, the wavelengths must be appropriate for the selected device.
  • Page 124 Quanta-Ray MOPO-HF Optical Parametric Oscillator —allows you to set a peak value for the refer to the : SET: PEAK PO-PD ( “Threshold Table-Writing Procedure” on page 6-31). Once selected, the screen changes to show the master and power oscillator output as shown below.

  • Page 125: The Remote Menu

    Operation The Remote Menu Select the REMOTE menu OPERATE OPERATE1 REMOTE SETUP MONITOR1 SELECT IEEE488 BAUD LOCAL 2400 MONITOR Select the remote Set the IEEE488 Set the baud rate interface or address local Figure 6-7: The Remote Menu The Remote menu is accessed by pressing the button three times.

  • Page 126: Figure 6-8: Returning Local Control To The System

    Quanta-Ray MOPO-HF Optical Parametric Oscillator Current MOPO or FDO output Current Signal or Idler output OPERATE 500.000 OPERATE1 SETUP1 SETUP 1220.814nm MONITOR1 LOCAL MONITOR Returns control to front panel Figure 6-8: Returning Local Control to the System 1. Press to place the cursor under the digit to be changed. 2.

  • Page 127: The Monitor1 Menu

    Operation The Monitor1 Menu MO output power, MO output power, Select the MONITOR1 menu Signal wavelength total and average total and average OPERATE M_OSC P_OSC 500000 OPERATE1 REMOTE 1428 7350 SETUP MONITOR1 START MOPO SCAN TABLE MONITOR Start, hold, resume Select the algorythm and abort a scan for driving the MOPO...

  • Page 128: Switching Between Mopo And Fdo Operation

    Quanta-Ray MOPO-HF Optical Parametric Oscillator Switching Between MOPO and FDO Operation Switching from MOPO to FDO Operation 1. Set system mode to a. From the Service1 menu, press the button, then use the up/ MODE down buttons to select b. Press the button until it beeps to activate this selection.

  • Page 129: Running A Scan

    Operation Running a Scan Figure 6-10 shows a scan being initiated from the Operate1 menu, and the following procedure explains how to perform a scan. Select OPERATE1 Indicates scan Indicates Track Current MOPO or FDO output Current Signal or Idler output menu progression or Table mode...

  • Page 130: Operating At Fixed Wavelengths

    Quanta-Ray MOPO-HF Optical Parametric Oscillator percentage of scan completed, and the wavelength display shows the progress of the signal or idler output or, if in the Operate2 menu MODE is set to the doubled signal or idler output. Fraction of current Current MOPO or FDO output scans complete Current Signal or Idler output...

  • Page 131: Mopo Table-Writing Procedures

    Operation MOPO Table-Writing Procedures Please read this entire section on table-writing procedure before you write a table for the first time. For the MOPO-HF to operate properly, accurate “look-up” tables must be implemented. These tables are used to position the master and power oscil- lator crystals and other MOPO-HF FDO devices at angles necessary for optimal operation at every wavelength.

  • Page 132: General Table-Writing Procedure

    Quanta-Ray MOPO-HF Optical Parametric Oscillator scan is complete. This routine can take quite a while to run, depending on the size of the scan range. For normal day-to-day operation, only use the “Automatic Table-writing Procedure.” This will keep your user table optimized and up-to-date. General Table-Writing Procedure First, verity the system is in track mode, then select a device for which you want to write a set of user table values, then select the table-writing method...

  • Page 133: Reloading The Theoretical Table Values

    Operation If not already at the begin scan point, the system will move there first. Once at the begin scan point (note the wavelength shown on the menu screen), use the up/down buttons to modify the position of the selected crystal (except for which does this automatically).

  • Page 134: Re-Establishing User-Defined Tables

    Quanta-Ray MOPO-HF Optical Parametric Oscillator b. Press and hold the button until it beeps. DEVICE 4. Delete the existing tables. a. Press the button to select it, then press it again and hold it METHOD in until it beeps. b. Press and hold the button until it beeps.

  • Page 135: Lagrangian Table-Writing Procedure

    Operation Lagrangian Table-Writing Procedure If oscillation of the master oscillator is not observed at 440 and/or 690 nm, use the following Lagrangian curve-fitting routine to “refine” the tables. 1. From the Setup1 menu, verify that 460 nm and 660 nm are entered for wavelength scan values.
  • Page 136 Quanta-Ray MOPO-HF Optical Parametric Oscillator Toward the red end of the spectrum the MO detector may register small leakage signals from the power oscillator that must also be detected and discriminated against. The system calculates the threshold using the following procedure. First, a baseline is created by recording the signal levels of the MO and PO detec- tors over the entire wavelength range, provided the MO is not oscillating.

  • Page 137: Automatic Table-Writing Procedure

    Operation b. Press and hold the button until it beeps to activate your MOPO selection. 6. Press and hold the button until it beeps to re-enter the peak- SET: PEAK ing routine. 7. Press the . button to go to the wavelength(s) for which the system CONT does not appear optimized and independently optimize the position of the master and power oscillator crystals.
  • Page 138 Quanta-Ray MOPO-HF Optical Parametric Oscillator To perform the automatic table-writing process (which OPO_AUTO includes both the MO and PO tables): 1. Verify the system is set to track mode. a. If necessary, from the Monitor1 menu, press the button, MOPO then use the up/down buttons to scroll to TRACK b.

  • Page 139: Chapter 7: Maintenance

    Chapter 7 Maintenance Preventative Maintenance • The MOPO-HF top cover protects the internal components from out- side contamination and prevents unwanted stray optical radiation from escaping the system. • The MOPO-HF should always be operated with the top cover in place. •...

  • Page 140: Cleaning Optical Components

    Quanta-Ray MOPO-HF Optical Parametric Oscillator Stick to the following principles whenever you clean any optical surface: • Remove and clean one optical element at a time. If all of the optics are removed and replaced as a group, all reference points will be lost, making realignment extremely difficult.
  • Page 141 Maintenance 3. Wipe one surface—bottom to top—in a single motion. Be careful that the tip of the hemostat does not scratch the surface. 4. Repeat this operation with a clean tissue on the second optic surface. Note: a clean optical surface will scatter little or no light when the laser is operating.
  • Page 142 Quanta-Ray MOPO-HF Optical Parametric Oscillator...

  • Page 143: Chapter 8 Service And Repair

    Chapter 8 Service and Repair The Quanta-Ray MOPO-HF is a Class IV—High Power Laser Product Danger! whose beam is, by definition, a safety and fire hazard. Take precautions Laser Radiation to prevent accidental exposure to both direct and reflected beams. Dif- fuse as well as specular beam reflections can cause severe eye or skin damage.

  • Page 144: Part 1

    Quanta-Ray MOPO-HF Optical Parametric Oscillator Part 1 Symptom Cause MOPO-HF Low pump power. No output from the Motor mike is at the end of its range. Damaged optics. Damaged crystal. Low output power from the Low pump power. MOPO-HF Master oscillator is not seeding the power oscillator. Power oscillator seeding is not optimized.

  • Page 145: Part 2

    Service and Repair Symptom Cause Amplitude instability PRO-S eries pump source is unstable. Master oscillator seed beam is misaligned. Master oscillator output power is low. Master oscillator output is unstable. Power oscillator crystal angel is not optimized. There is excessive dither amplitude. Master oscillator is not locking Master oscillator output power is low.
  • Page 146 Quanta-Ray MOPO-HF Optical Parametric Oscillator Cause of Symptom Corrective Action Harmonic generator detuned. While viewing the pump power monitor, optimize the second and third harmonic crystal angles. Adjust the gain potentiometer on the back of the detector. Insufficient signal level on detector.

  • Page 147: Replacement Parts

    Service and Repair Replacement Parts The following list of parts can be purchased and installed by the user. They are offered here in the event an item becomes damaged or lost, or when an additional item is required that was not purchased with the system. Table 8-1: Replacement Parts Description Part Number...
  • Page 148 Quanta-Ray MOPO-HF Optical Parametric Oscillator Table 8-1: Replacement Parts Description Part Number Window, AR 355 nm 0449-1910 BBHR, 100 cm, CC/PL 0449-2670 Filter, ND, 0.1% 0449-4640 Filter, ND, 1% 0449-4641 Filter, ND, 3% 0449-4642 Filter, ND, 10% 0449-4643 Filter, Band Pass, 360 nm 0449-4670 Filter, Heat Absorbing 0449-4680...

  • Page 149: Chapter 9 Customer Service

    Chapter 9 Customer Service Customer Service At Spectra-Physics, we take great pride in the reliability of our products. Considerable emphasis has been placed on controlled manufacturing meth- ods and quality control throughout the manufacturing process. Neverthe- less, even the finest precision instruments will need occasional service. We feel our instruments have excellent service records compared to competi- tive products, and we hope to demonstrate, in the long run, that we provide excellent service to our customers in two ways: first by providing the best...

  • Page 150: Return Of The Instrument For Repair

    Quanta-Ray MOPO-HF Optical Parametric Oscillator will provide at its expense all parts and labor and one-way return shipping of the defective part or instrument (if required). In-warranty repaired or replaced equipment is warranted only for the remaining unexpired portion of the original warranty period applicable to the repaired or replaced equip- ment.

  • Page 151: Service Centers

    Customer Service Service Centers Benelux Telephone: (31) 40 265 99 59 France Telephone: (33) 1-69 18 63 10 Germany and Export Countries Spectra-Physics GmbH Guerickeweg 7 D-64291 Darmstadt Telephone: (49) 06151 708-0 Fax: (49) 06151 79102 Japan (East) Spectra-Physics KK East Regional Office Daiwa-Nakameguro Building 4-6-1 Nakameguro...
  • Page 152 Quanta-Ray MOPO-HF Optical Parametric Oscillator...

  • Page 153: Appendix A: Installing The Bbo Crystal

    Appendix A Installing the BBO Crystal Due to cost and fragility, only a qualified spectra physics service engineer should perform the crystal installation described below. Determining the Orientation of the Optical Axis in the Crystal: Since BBO is a birefringent crystal, it exhibits a characteristic optical prop- erty known as double refraction.

  • Page 154: Figure A-2: The Light Walking Away From The Optical Axis

    Quanta-Ray MOPO-HF Optical Parametric Oscillator BBO Xtal Optic Axis L i g h t R ( R e f l e c t e d f r o m L i n e ) L i n e L i n e V i e w e r V i e w e r Optic Axis BBO Xtal...

  • Page 155: A Quick Verification Of The C-Axis Direction

    Installing the BBO Crystal A Quick Verification of the C-axis Direction As described in Chapter 3, light that enters a birefringent crystal will, in general, decompose into two distinct light rays: the extraordinary (e-) and ordinary (o-) rays. This results in a double (or split) image of an object when it is viewed through the crystal.

  • Page 156: Installing The Crystal In The Mount

    Quanta-Ray MOPO-HF Optical Parametric Oscillator Installing the Crystal in the Mount Master Oscillator 1. Place the pinhole aperture on the other side of the mount so that the flat side of the aperture faces the interior of the base plate. This allows the reference beam retroreflections to be viewed on the flat side of the aperture during subsequent stages of the alignment proce- dure.

  • Page 157: Power Oscillator

    Installing the BBO Crystal crystal orientation where the retroreflection closest to the center of displaced to the left-hand side by about 30 mm. Note that both reflections miss the aperture mount completely (Figure A-6). 30 mm Pinhole Retroreflections from the crystal surfaces Figure A-6: The HeNe beam retroreflections from the crystal for case Case C: The crystal is marked “L.”...
  • Page 158 Quanta-Ray MOPO-HF Optical Parametric Oscillator...

  • Page 159: Appendix B The Rs-232/Ieee-488 Interface

    Appendix B The RS-232/IEEE-488 Interface This appendix explains how to operate the MOPO-HF system from a remote source using either the optional RS-232 serial interface or IEEE- 488 parallel interface, the latter commonly referred to as the General Pur- pose Interface Bus, or GPIB. The parallel interface is much faster than the serial interface, but at the control speeds required by the MOPO-HF sys- tem, either is acceptable.

  • Page 160: Interface Commands

    Quanta-Ray MOPO-HF Optical Parametric Oscillator Interface Commands The following list of remote commands and queries provide full control of the MOPO-HF system through either the RS-232 serial or IEEE-488 paral- lel interface. Effort has been made to create an interface that is compliant with IEEE- 488.2.

  • Page 161: Ieee-488.2 Mandatory Commands

    The RS-232/IEEE-488 Interface :abort abort scan, goto, or table-writing operation :exegoto execute goto :recall x recall parameter setting :save x save parameters to file number x :movfwr move forward l µm :movbwr move backward l µm :mmovfwr micro-move forward 2 µsteps :mmovbwr micro-move backward 2 µsteps :wnmovfwr...

  • Page 162: Installation

    Quanta-Ray MOPO-HF Optical Parametric Oscillator Installation RS-232-C Interface The MOPO-HF RS-232 interface is configured as data communications equipment (DCE). Table B-1 at the end of this appendix describes the inter- face connectors and cabling. The serial communications port of a typical computer is configured as data terminal equipment (DTE).

  • Page 163: Selection (Rs232, Ieee, Local

    The RS-232/IEEE-488 Interface Selection (RS232, IEEE, LOCAL) Use the Remote menu to select the system control source. The default set- ting from the factory is the front panel, or , but the setting can be LOCAL changed so that the MOPO-HF can be controlled from a serial device, such as a terminal or a personal computer configured as a terminal, or an IEEE- 488 parallel control source.

  • Page 164: Initialization

    Quanta-Ray MOPO-HF Optical Parametric Oscillator Initialization After turning on the MOPO-HF controller and selecting either RS-232 or IEEE-488 control, initialize the computer interface as outlined below. Procedure to Initialize the Interface If the IEEE-488 interface is used, send the Select Device Clear bus command.

  • Page 165: Format And Syntax Rules

    The RS-232/IEEE-488 Interface Format and Syntax Rules Format All messages sent to the MOPO-HF must be transmitted in ASCII format. The MOPO-HF also sends back all response data in ASCII format. Syntax The syntax of the messages sent must conform exactly to the syntax of the examples shown in the next section on Command and Query Messages.
  • Page 166 Quanta-Ray MOPO-HF Optical Parametric Oscillator '---------------------------------------------------------------------------- 'CONTINUOUS SCAN SETUP '---------------------------------------------------------------------------- ScanBegin = 255! 'Start at 255.000 nm ScanEnd = 260! 'Stop at 260.000 nm Rate = .1 '100 picometers/second Shots = 0 'Continuous scan Scans = 2 'Make two passes PRINT #1, ":source:begin", ScanBegin PRINT #1, ":source:end", ScanEnd PRINT #1, ":source:rate", Rate...

  • Page 167: Sample Programs

    The RS-232/IEEE-488 Interface '--------------------------------------------------------------------------- 'MONITOR OPERATING STATUS '--------------------------------------------------------------------------- PRINT #1, ":read:wlen?" GOSUB ReadData PRINT #1, ":read:count?" GOSUB ReadData PRINT #1, ":read:power?" GOSUB ReadData '--------------------------------------------------------------------------- 'READ DATA SUBROUTINE '--------------------------------------------------------------------------- 'Inputs: None 'Outputs: Response$ ReadData: Chars$ = "" NewChar$ = "" WHILE NewChar$ <> CHR$(10) 'Loop until LF is receiving Response$ = Chars$ 'Save all but the LF char...
  • Page 168 Quanta-Ray MOPO-HF Optical Parametric Oscillator TotalLoop: FOR multiloop = 1 TO multiloopmax TotalLoops = TotalLoops + 1 PRINT “MOPO SERIAL COMMUNICATIONS TEST AND DEMO PROGRAM” PRINT “multiLoop number “; multiloop; “ of “, multiloopmax PRINT “Total loops”; TotalLoops PRINT PRINT #1, “ “...
  • Page 169 The RS-232/IEEE-488 Interface REM GOTO IncrScanSetup: ‘---------------------------------------------------------- ‘CONTINUOUS SCAN SETUP ‘---------------------------------------------------------- PRINT PRINT “Setting up continuous scan of signal range” PRINT “TotalLoops=”; TotalLoops, “MultiLoop=”; multiloop PRINT ‘****************************************************************** ‘ Test scanning through signal range (continuous) ‘ This scan involves the crystal switch and should provide ‘...
  • Page 170 Quanta-Ray MOPO-HF Optical Parametric Oscillator PRINT “----------------------------------” PRINT “Parameter Sent Received” PRINT “----------------------------------” PRINT “Begin”, ScanBegin, Response1 PRINT “End”, ScanEnd, Response2 PRINT “Rate”, Rate, Response3 PRINT “Shots”, Shots, Response4 PRINT “Scans”, scans, Response5 PRINT IF faultflag = 1 THEN PRINT “Continuous Scan ... Setup ERROR” PRINT “Program Terminated”...
  • Page 171 The RS-232/IEEE-488 Interface ‘---------------------------------------------------------- ‘INCREMENTAL SCAN SETUP VERIFICATION ‘---------------------------------------------------------- GOSUB ReadSetup faultflag = 0 IF Response1 <> ScanBegin THEN faultflag = 1 IF Response2 <> ScanEnd THEN faultflag = 1 IF Response6 <> Increment THEN faultflag = 1 IF Response4 <> Shots THEN faultflag = 1 IF Response5 <>...
  • Page 172 Quanta-Ray MOPO-HF Optical Parametric Oscillator ‘---------------------------------------------------------- ‘SAVE AND RECALL ‘---------------------------------------------------------- PRINT “Saving parameter setup...”; TotalLoops; “ total loops” PRINT PRINT #1, “:save 3”‘ ‘Save current operating parameters ‘into non-volatile memory as setup ‘record #3. PRINT “Recalling parameter setup...”; TotalLoops; “ total loops” PRINT PRINT #1, “:recall 4”...
  • Page 173 The RS-232/IEEE-488 Interface GOSUB readdata Response3 = VAL(response$) PRINT #1, “:source:shots?” GOSUB readdata Response4 = VAL(response$) PRINT #1, “:source:scans?” GOSUB readdata Response5 = VAL(response$) PRINT #1, “:source:incr?” GOSUB readdata Response6 = VAL(response$) RETURN ‘---------------------------------------------------------- ‘READ DATA SUBROUTINE ‘---------------------------------------------------------- ‘Inputs: None ‘Outputs: Response$ readdata: Chars$ = ““...
  • Page 174 Quanta-Ray MOPO-HF Optical Parametric Oscillator count = VAL(response$) PRINT #1, “:read:wlen?” GOSUB readdata wl = VAL(response$) PRINT type$; TotalLoops; multiloop; “/”; multiloopmax; “ “; count; “ “; wl WEND WHILE count <> 0 ‘Wait for last scan to finish IF DoWaits THEN GOSUB WaitFiveSeconds PRINT #1, “:read:count?”...
  • Page 175 The RS-232/IEEE-488 Interface CONST EERR = &H8000 ‘Error detected CONST TIMO = &H4000 ‘Timeout DECLARE SUB IBCLR (BYVAL BD%) DECLARE SUB IBFIND (BDNAME$, BD%) DECLARE SUB IBRD (BYVAL BD%, RD$) DECLARE SUB IBWRT (BYVAL BD%, WRT$) DECLARE SUB GpibError (Msg$) DECLARE SUB MopoError (Msg$) PRINT “GPIB initialization”...
  • Page 176 Quanta-Ray MOPO-HF Optical Parametric Oscillator ‘---------------------------------------------------------- ‘ START OF MULTILOOP ‘---------------------------------------------------------- TotalLoop: FOR multiloop = 1 TO multiloopmax TotalLoops = TotalLoops + 1 PRINT “DOUBLER GPIB COMMUNICATIONS TEST AND DEMO PROGRAM” PRINT “multiLoop number “; multiloop; “ of “, multiloopmax PRINT “Total loops”;...
  • Page 177 The RS-232/IEEE-488 Interface PRINT “GOTO running...” PRINT PRINT “Going to “; GotoWL PRINT Wavelength = 0 STB = 1 ‘anything other than zero REM WHILE (Wavelength <> GotoWL!) ‘old-style Wait for GOTO to finish WHILE (STB <> 0) ‘wait for GOTO to finish Cmd$ = “:read:wlen?”...
  • Page 178 Quanta-Ray MOPO-HF Optical Parametric Oscillator Rate = .1 ‘100 picometers/second Shots = 0 ‘Continuous scan scans = 2 ‘Make two passes Cmd$ = “:source:begin” + STR$(ScanBegin) GOSUB WriteMopo Cmd$ = “:source:end” + STR$(ScanEnd) GOSUB WriteMopo Cmd$ = “:source:rate” + STR$(Rate) GOSUB WriteMopo Cmd$ = “:source:shots”...
  • Page 179 The RS-232/IEEE-488 Interface PRINT “Program Terminated” END IF ‘---------------------------------------------------------- ‘CONTINUOUS SCAN ‘---------------------------------------------------------- Cmd$ = “:scan” GOSUB WriteMopo PRINT “Continuous scan running...” PRINT type$ = “Cont:” GOSUB WaitForScan IncrScanSetup: ‘---------------------------------------------------------- ‘INCREMENTAL SCAN SETUP ‘---------------------------------------------------------- PRINT “Setting up incremental scan...” PRINT ScanBegin = 220 + multiloop ScanEnd = 240 + multiloop Increment = 2 ‘2 nanometer steps...
  • Page 180 Quanta-Ray MOPO-HF Optical Parametric Oscillator ‘---------------------------------------------------------- ‘INCREMENTAL SCAN SETUP VERIFICATION ‘---------------------------------------------------------- GOSUB ReadSetup faultflag = 0 IF Response1 <> ScanBegin THEN faultflag = 1 IF Response2 <> ScanEnd THEN faultflag = 1 IF Response6 <> Increment THEN faultflag = 1 IF Response4 <>...
  • Page 181 The RS-232/IEEE-488 Interface ‘---------------------------------------------------------- ‘SAVE AND RECALL ‘---------------------------------------------------------- PRINT “Saving parameter setup...”; TotalLoops; “ total loops” PRINT Cmd$ = “:save 3” ‘Save current operating parameters ‘into non-volatile memory as setup ‘record #3 GOSUB WriteMopo PRINT “Recalling parameter setup...”; TotalLoops; “ total loops” PRINT Cmd$ = “:recall 4”...
  • Page 182 Quanta-Ray MOPO-HF Optical Parametric Oscillator ‘********************************************************** ‘ SUBROUTINES ‘********************************************************** ‘---------------------------------------------------------- ‘READ SETUP SUBROUTINE ‘---------------------------------------------------------- ReadSetup: PRINT “Verifying setup...” PRINT Cmd$ = “:source:begin?” GOSUB WriteMopo GOSUB ReadMopo Response1 = VAL(Response$) Cmd$ = “:source:end?” GOSUB WriteMopo GOSUB ReadMopo Response2 = VAL(Response$) Cmd$ = “:source:rate?” GOSUB WriteMopo GOSUB ReadMopo Response3 = VAL(Response$)
  • Page 183 The RS-232/IEEE-488 Interface ‘---------------------------------------------------------- ‘WRITE SUBROUTINE (GPIB) ‘---------------------------------------------------------- ‘Inputs: Cmd$ ‘Outputs: None WriteMopo: CALL IBWRT(Mopo%, Cmd$) IF (IBSTA% AND EERR) THEN CALL GpibError(“IBWRT ERROR”) RETURN ‘---------------------------------------------------------- ‘READ SUBROUTINE (GPIB) ‘---------------------------------------------------------- ‘Inputs: None ‘Outputs: Response$ ReadMopo: Response$ = SPACE$(40) CALL IBRD(Mopo%, Response$) IF (IBSTA% AND EERR) THEN CALL GpibError(“IBRD ERROR”) RETURN ‘----------------------------------------------------------...
  • Page 184 Quanta-Ray MOPO-HF Optical Parametric Oscillator WHILE Count <> 0 ‘Wait for last scan to finish IF DoWaits THEN GOSUB WaitFiveSeconds Cmd$ = “:read:count?” GOSUB WriteMopo GOSUB ReadMopo Count = VAL(Response$) Cmd$ = “:read:wlen?” GOSUB WriteMopo GOSUB ReadMopo Wl = VAL(Response$) PRINT type$;...

  • Page 185: Connections

    The RS-232/IEEE-488 Interface Connections Table B-1: IBM-PC/AT Serial Port Pinout Computer or Terminal MOPO-HF/FDO RS-232-C Signal Pin No. Pin No. Pin No. Signal Signal Name (25-Pin) (9-Pin) Transmit Data Receive Data Request To Send Clear To Send Data Set Ready Data Carrier Detect Data terminal Ready Signal Ground...
  • Page 186 Quanta-Ray MOPO-HF Optical Parametric Oscillator B-28...

  • Page 187: Appendix C: Replacing The Pcmcia Card Battery

    Appendix C Replacing the PCMCIA Card Battery The 512 kB PCMCIA memory card found in the MOPO-HF controller uses a small 3 V disk battery to maintain the data stored in it. The expected lifetime of the battery is approximately 2–3 years, so it is prudent to change the battery every 2 years regardless of use.

  • Page 188: Procedure

    Quanta-Ray MOPO-HF Optical Parametric Oscillator Epson Plain gray card with black edge trim. Latch retains battery. Battery: CR2025 Epson One side white, opposite side light blue. Latch retains battery. Battery: CR2025 Epson One side green/brown/copper, opposite side brown. Latch retains battery. Battery: BR2325 Panasonic BN-512HMC Gray and green with gray edge trim.
  • Page 189 Replacing the PCMCIA Card Battery 1. With the controller power on and the PCMCIA card in the unit, either loosen the screw (Mitsubishi or Panasonic) or slide the latch that retains the battery. Do not drop the screw on the motherboard! 2.
  • Page 190 Quanta-Ray MOPO-HF Optical Parametric Oscillator...

  • Page 191: Appendix D: Manually Controlling The Crystal Stage

    Appendix D Manually Controlling the Crystal Stage The Autotrack pc board in the MOPO-HF controller has two sets of four switches. One set controls the PO crystal, the other the MO crystal. Each set is identical in how it operates. The following outlines the operation of one of these sets.
  • Page 192 Quanta-Ray MOPO-HF Optical Parametric Oscillator...

  • Page 193: Appendix E Determining Telescope Lenses For The Po

    Appendix E Determining Telescope Lenses for the PO The following procedure is provided so you can select the proper lens com- bination for your power oscillator (PO) telescope if your system has not been previously setup and aligned or has had its configuration changed. Measure the 355 nm energy in the power oscillator leg.
  • Page 194 Quanta-Ray MOPO-HF Optical Parametric Oscillator 2. Choose from the following list of lens combination in accordance with the pump energy measured in Step 1j: Energy Range (mJ)Positive/Negative Lens (mm fl)Part Numbers ≤ 200 +150/–100 (1.5x) 0448-8870 0448-8890 200–300 +200/–150 (1.3x) 0448-8860 0448-8880 300–350 +240/–200 (1.2x)

  • Page 195: Appendix F: Installing A Software Upgrade

    Appendix F Installing a Software Upgrade New releases of the MOPO-HF controller software might be issued that will upgrade your system to add new capabilities or increase its perfor- mance. If this occurs, use the following procedure to install the new soft- ware.
  • Page 196 Quanta-Ray MOPO-HF Optical Parametric Oscillator 5. Turn on the controller. The new software will boot. 6. Once the opening menu is displayed, press the button until OPERATE the Service1 menu is displayed. 7. Leaving the system on, replace the new PCMCIA card with the origi- nal card.

  • Page 197: Notes

    Notes Notes-1...
  • Page 198 Quanta-Ray MOPO-HF Optical Parametric Oscillator Notes-2...
  • Page 199 Notes Notes-3...
  • Page 200 Quanta-Ray MOPO-HF Optical Parametric Oscillator Notes-4...
  • Page 201 Notes Notes-5...
  • Page 202 Quanta-Ray MOPO-HF Optical Parametric Oscillator Notes-6...

  • Page 203: Problems And Solutions

    Report Form for Problems and Solutions We have provided this form to encourage you to tell us about any difficulties you have experienced in using your Spectra-Physics instrument or its manual—problems that did not require a formal call or letter to our service department, but that you feel should be remedied. We are always interested in improving our products and manuals, and we appreciate all suggestions.

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