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MOGlabs DLC202 Manual

External cavity diode laser controller
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External Cavity Diode Laser Controller
DLC102, DLC202, DLC252, DLC502
Revision 9.09

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  • Page 1 External Cavity Diode Laser Controller DLC102, DLC202, DLC252, DLC502 Revision 9.09...
  • Page 2 MOGL Contact For further information, please contact: MOG Laboratories P/L MOGLabs USA LLC MOGLabs Europe 18 Boase St 419 14th St Goethepark 9 Brunswick VIC 3056 Huntingdon PA 16652...
  • Page 3 MOGL...

  • Page 5: Safety Precautions

    Safety Precautions Safe and effective use of this product is very important. Please read the following safety information before attempting to operate your laser. Also please note several specific and unusual cautionary notes before using the , in addition to the safety precautions MOGL that are standard for any electronic equipment or for laser-related instrumentation.
  • Page 6 removed from the controller when it is in the clockwise ( position. • To completely shut off power to the unit, turn the keyswitch anti-clockwise ( position), switch the mains power STANDBY switch at rear of unit to , and unplug the unit. •...

  • Page 7: Protection Features

    Protection Features includes a number of features to protect you and MOGL your laser. Softstart A time delay (3 s) followed by linearly ramping the diode cur- rent (3 s max). Circuit shutdown Many areas of the circuitry are powered down when not in use. The high voltage supply and piezo drivers, the diode current supplies, the coil driver, and others are without power when the unit is in standby mode, if an interlock is open, or a fault...
  • Page 8 Protection relay When the power is off, or if the laser is off, the laser diode is shorted via a normally-closed solid-state relay at the laser head board. Emission indicator The abs controller will illuminate the emission warn- MOGL ing indicator immediately when the laser is switched on.

  • Page 9: Table Of Contents

    Contents Preface Safety Precautions Protection Features 1 Introduction 1.1 Basic operation ..... . 1.2 Passive frequency control ....locking to an atomic transition .
  • Page 10 Contents viii 3.8 External control of lock frequency setpoint ..4 Optimisation 4.1 Frequency reference ....4.2 Noise spectra ..... . . A Specifications response .
  • Page 11 Contents G.3 RF coupling ......H Feedback overview Connector pinouts Laser ......Photodetector .
  • Page 12 Contents...

  • Page 13: Introduction

    TEC voltage C ° e r r e r r l i F r e t r o r Figure 1.1: MOGLabs front panel layout.

  • Page 14: Passive Frequency Control

    Chapter 1. Introduction STACK 120V SPAN SPAN FREQUENCY TRIG time Figure 1.2: Stack (or current bias) output and trigger pulse, when scan- ning. Note that the ramp slope can be inverted. Details of the ramp behaviour are described in section A.2. 1.2 Passive frequency control controls the laser frequency via the diode current, MOGL...
  • Page 15 1.2 Passive frequency control Ch1 100mV Ch2 100mV 5.0ms Figure 1.3: A simple absorption spectrum of rubidium with the controller in simple frequency scanning mode. ator ( ) and thus the mid-point frequency of the sweep. As the STACK external cavity frequency changes, the laser may “mode-hop” due to competition between the external cavity and the internal cavity defined by the rear and front facets of the diode saemiconductor chip itself.

  • Page 16: Dc Locking To An Atomic Transition

    Chapter 1. Introduction locking to an atomic transition Figure 1.4 shows one possible configuration in which a MOGL is used to lock an to an atomic transition. Locking is to ECDL the side of an absorption peak in a vapour cell; see for example Demtr¨...

  • Page 17: Ac Locking To An Atomic Transition

    locking to an atomic transition locking to an atomic transition With locking ( demodulation or “lock-in amplifier” detection), the laser frequency can be locked to a peak centre. The proach offers the advantage of inherently lower detected noise and thus the potential for improved laser frequency stability. The setup is similar to that for locking, but modulation of the laser fre- quency, or the reference frequency, is required.
  • Page 18 Chapter 1. Introduction...

  • Page 19: Connections And Controls

    2. Connections and controls 2.1 Front panel controls l o r r e l a t l e r r r r u TEC voltage C ° e r r e r r l i F r e t r o r STANDBY mode, the maintains the laser temperature, but...
  • Page 20 Chapter 2. Connections and controls CURRENT Diode injection current, 0 to 100/200/250/500 mA (DLC102 to DLC502). The response is not linear; that is, the change in current varies for a given rotation of the knob. The mid-range sensitivity is reduced to allow greater precision at normal operating currents.
  • Page 21 2.1 Front panel controls INPUT OFFSET Offset of input light intensity signal, 0 to 10 V. This can be ad- justed to bring the photodetector light signal close to zero on the oscilloscope, and to shift the zero frequency lockpoint for locking.

  • Page 22: Front Panel Display/Monitor

    Chapter 2. Connections and controls 2.2 Front panel display/monitor Display selector includes a high-precision 4.5 digit display MOGL with four unit annunciators and 8-channel selector switch. Current * see note below Diode current (mA) Curr max Current limit (mA) ( ) sign indicates limit rather than actual current Voltage Diode voltage (V) ◦...
  • Page 23 2.2 Front panel display/monitor CHAN A Several important signals can also be monitored externally with an oscilloscope via the rear connectors CHANNEL A CHANNEL B . The outputs to these can be selected with the TRIG CHAN A selectors. CHAN B Input Photodetector [30 mV/µW] Filter...

  • Page 24: Rear Panel Controls And Connections

    Chapter 2. Connections and controls 2.3 Rear panel controls and connections l o r r e l o l r a r t a i l : l e r o t a i r IEC power in/out The unit should be preset for the appropriate voltage for your coun- try.
  • Page 25 2.3 Rear panel controls and connections TRIG Oscilloscope trigger, -level. Connect to external trigger input on oscilloscope. Set oscilloscope triggering for external, rising edge. Diode current limit. The current limit can be set with the display selector set to Curr max. See page 10 for further information. ERROR CURR MOD Input for externally derived feedback error signal (...
  • Page 26 Chapter 2. Connections and controls are recommended; usually 10 or 20 Hz works well but if ringing is observed at the start of the sweep, reduce f sweep . Connection to external modulator, output is 0 to ±500 mA, ±8 V. MOD OUT Current sensing with 1 Ω...

  • Page 27: Internal Switches And Adjustments

    2.4 Internal switches and adjustments 2.4 Internal switches and adjustments See appendix H for schematic overviews of the piezo and diode current control signals, and the effect of the different switches. See appendix J for the location of relevant internal components. CAUTION The cover of the controller should be left on, even loosely, to ensure proper airflow and cooling.
  • Page 28 Chapter 2. Connections and controls DIP 1, 2 Please refer to section 2.5 below for discussion of feedback config- urations. DIP 3 With , the 250 kHz modulator directly modulates the injec- DIP 3 ON tion current to cause frequency modulation of the laser frequency. In conjunction with a frequency-dependent absorption on the photode- tector signal, for example with an atomic vapour cell or etalon (see section 3.5).
  • Page 29 2.4 Internal switches and adjustments DIP 6 and DIP 12 If both are on, internal slow feedback to , and external DIP 6,12 STACK current modulation to the diode current, are enabled. DIP 7 Switch determines whether (centre or top of peak) or (side of peak) locking is used.
  • Page 30 Chapter 2. Connections and controls reverse the error signal. See section 2.5 below for further discussion. DIP 12 Current feedback is normally AC coupled because slow feedback to takes care of slow drifts. For lasers without piezo control, STACK such as DBR and DFB diodes, DC feedback to current can be en- abled by switching on.
  • Page 31 2.4 Internal switches and adjustments Use switch (current feed-forward bias) to drive the current with DIP 4 the scanning ramp. Switch adds the fast signal to the DIP 16 DISC current. can be active simultaneously. Switch DIP 16 DIP 4 enables coupling of the current feedback, rather than the default coupling, to allow current-only feedback locking.

  • Page 32: Feedback Configurations

    Chapter 2. Connections and controls 2.5 Feedback configurations is designed to drive up to three feedback actuators with ap- propriate frequency bandwidths for each. The actuators are STACK . Suitable lasers include the which MOGL DISC CURRENT ECDL feedback but no piezo;...
  • Page 33 2.5 Feedback configurations slow, fast STACK DISC 20 dB/decade, BW 50 Hz STACK 40 dB/decade, BW 1.5 kHz DISC 20 dB/decade, BW 15 kHz CURRENT slow, fast, extra STACK DISC CURRENT 20 dB/decade, BW 50 Hz STACK 40 dB/decade, BW 1.5 kHz DISC 20 dB/decade BW 15 kHz + flat response CURRENT...
  • Page 34 Chapter 2. Connections and controls only CURRENT : fixed STACK : fixed DISC : flat, BW 15 kHz CURRENT 12 should be feedback. DC CURRENT to drive the current with the scanning ramp. For DBR and DFB lasers and ECDLs when it is desirable to operate without piezo actuators.

  • Page 35: Digital Control

    2.6 Digital control 2.6 Digital control HD12 is a 10-pin header which provides access to several control signals for locking and for sample-and-hold of the lock-point. HD12 is located near the switches, slightly towards the front and left- hand side of the unit (see appendix J). The pinout of the header is described in section I.4.

  • Page 36: Internal Trimpots

    Chapter 2. Connections and controls 2.7 Internal trimpots Current dither amplitude limit RT12 Phase lead RT13 Ambient temp for active sensors (AD590, AD592) RT15 current limit locking, either the laser frequency or the external reference must be modulated at the dither frequency, 250 kHz.

  • Page 37: Operation

    3. Operation 3.1 Simplest configuration In the simplest application, the will be used to con- MOGL trol just the diode injection current and temperature. All connections are via a single cable to the abs laser. If using with a non- MOGL abs laser, please see appendix G for information on connecting MOGL...

  • Page 38: Laser Frequency Control

    Chapter 3. Operation the time to equilibrate the temperature ( output, CHANNEL B Temp front panel set to ) after a sudden change in T CHAN B 6. Adjust the current control knob to minimum (fully anti-clockwise). Curr max 7. Set the diode maximum current: select on the display selector, then adjust the maximum allowed diode injection cur- rent via the rear panel I...

  • Page 39: External Scan Control

    3.3 External scan control Several adjustments of the frequency sweep are possible: switch should be on SCAN LOCK SCAN LOCK SCAN Offset; i.e. mid-point voltage of the ramp. FREQUENCY Sets the height of the ramp; see fig. 3.1. SPAN front-panel trimpot controls the feed- BIAS BIAS forward bias injection current which follows the...

  • Page 40: Locking To An Atomic Transition: Dc

    Chapter 3. Operation Saturated absorption spectrum for natural Rb −0.2 −2 Frequency (GHz) Figure 3.2: A saturated absorption spectrum of rubidium using a standard uncoated laser diode and low diffraction efficiency grating in Littrow con- figuration (upper trace). The lower trace shows the -modulation error signal (see §3.5).
  • Page 41 3.4 Locking to an atomic transition: λ/4 λ/4 Vapour cell Offsets ECDL Servo Figure 3.3: Schematic setup for locking to an atomic transition. PD photodetector. BS beamsplitter, M mirror, λ/4 retarder. is the background from a saturated absorption spectrum. Sample oscilloscope traces obtained in locking (“side of fringe”) mode are shown below, for wide and narrow spans.
  • Page 42 Chapter 3. Operation means, deflect a fraction of the laser output through the vapour cell. The is designed to operate best with about MOGL 250 µW incident on each of the Si-PIN photodiodes. Lensed and filtered photodiodes are standard, to minimise the influ- ence of background light, but best results will be obtained if light from incandescent or fluorescent lamps is eliminated.

  • Page 43: Locking To An Atomic Transition: Ac

    3.5 Locking to an atomic transition: 3.5 Locking to an atomic transition: Figures 3.5 and 3.6 show two alternate saturated absorption spec- troscopy arrangements, useful for (“top of fringe”) locking. The laser frequency can be directly modulated via the diode current (see §2.4, switch ), or using an external modulator.
  • Page 44 Chapter 3. Operation nal on . The is designed to operate MOGL CHANNEL A best with about 250 µW incident on the Si-PIN photodiode. Lensed and filtered photodiodes are standard, to remove most background light, and when locking at 250 kHz modula- tion frequency, any remaining photocurrent from background lighting should not be a problem.
  • Page 45 3.5 Locking to an atomic transition: Ch1 100m V Ch2 100m V 20.0m s Ch1 100m V Ch2 100m V 20.0m s Figure 3.7: Examples of spectra for locking, for wide and narrow spans (upper traces), with error signals (lower traces). mended;...

  • Page 46: External Sweep

    Chapter 3. Operation 3.6 External sweep An external ramp can be used to control the frequency sweep, for example if very slow sweeps are required, or for computer-controlled sweeps. To operate with external sweep: 1. The external sweep signal MUST have 1.25 V offset. That is, it must transition through 1.25 V at some time during the sweep.
  • Page 47 3.7 Locking using an external signal an error signal, usually with PID (proportional-integral-differential) or PIID (PID with a double integrator) response. When using an external error or control signal, it will normally be advisable to switch off the modulator ( switch 3.7.1 External error signal To operate with externally generated error signal, but using the...

  • Page 48: External Control Of Lock Frequency Setpoint

    Chapter 3. Operation 1. Connect fast control signal to ERROR 2. Enable fast current control with switch 3. Connect slow error signal to SWEEP 4. Enable slow piezo control with switch The piezo will be controlled by the is on SCAN LOCK SCAN...

  • Page 49: Optimisation

    4. Optimisation Laser frequency stabilisation is a complex and ongoing research topic. A thorough treatment would require extensive discussion of control theory, actuator response, mechanical design, laser-atom in- teractions and electronics. Here we consider the problem from a pragmatic perspective. The laser is assumed to be moderately stable, operating close to the desired frequency, with a linewidth of a few MHz averaged over a typical measurement time of about one second.
  • Page 50 Chapter 4. Optimisation produce clear (low-noise) dispersive error signals as shown in the upper trace of fig. 3.7. Note that the error signal should be about 0.5 V p-p. While the signal looks cleaner at larger amplitude relative to background oscilloscope noise, in fact the overall performance will deteriorate.

  • Page 51: Noise Spectra

    4.2 Noise spectra MOGLabs DLC-202 + ECD-003 monoblock laser noise spectra 1000.00 Unlocked 10.00 Piezo 1.00 Piezo & current 0.10 Off resonance 0.01 Frequency (Hz) Figure 4.1: Error signal spectra, with laser unlocked, locked with SLOW (piezo) feedback only, and with (piezo+current) feedback.
  • Page 52 Chapter 4. Optimisation onances, outside a Doppler absorption peak. The Off resonance spectrum gives the frequency discriminator noise floor: it is mean- ingless to try to reduce the laser frequency noise below this level. With feedback enabled, the noise for low Fourier frequencies SLOW is drastically reduced.

  • Page 53: A Specifications

    A. Specifications Specification Parameter Current regulator 0 to 100/200/250/500 mA Output current 3.2 V at full current; 6 V at half current Max diode voltage /HC models up to 6.5 V at full current ±0 01 mA Display resolution < 10 nA rms (10 Hz – 1 MHz) Noise Warmup time: 15 minutes Stability...
  • Page 54 Appendix A. Specifications Specification Parameter Piezos 0 to 120 V for (default) FREQUENCY STACK 0 to 150 V optional (LK2 removed) 100 ± 16 4 V feedback DISC 4 to 70 Hz Scan rate Note The default maximum piezo voltage is 120 V but can be increased to 150 V by removing jumper LK2;...
  • Page 55 Feedback system 250 kHz, ±8 V, ±500 mA MOD OUT Current output (1 Ω sense) Control via rear-panel trimpot I set ◦ 0 to 360 (min) PHASE 10 V to +10 V INPUT OFFSET ±0 5 V ERROR OFFSET ±20 dB MASTER ±20 dB GAIN...
  • Page 56 Appendix A. Specifications mains off, or fault condition DARK detected ( failure, polar- ity reversed, open-circuit, ca- ble unplugged, missing sen- sor, temperature out of range) STANDBY RUN LED mains power on Standby ORANGE (temperature controller on) Fully operational GREEN (piezo, current, ramp) Start sequence error or fault (Either...

  • Page 57: Rf Response

    response response RBW 30 kHz -30 dBm VBW 10 MHz Ref -20 dBm 50 dB SWT 17 s Center 1.5 GHz 300 MHz/ Span 3 GHz Figure A.1: response, input on laser headboard to diode SMA output. A.2 Sweep saturation and trigger In normal scanning mode, a sawtooth is supplied to the stack piezo (or other laser frequency actuator), at a frequency of 1 to 70 Hz;...
  • Page 58 Appendix A. Specifications STACK 120V SPAN TRIG time Figure A.2: output voltage and trigger pulse, when STACK FREQUENCY is set near the midpoint (upper) or moved closer to 0 V (lower), where the output voltage exceeds the maximum range.

  • Page 59: B Troubleshooting

    B. Troubleshooting detects a wide range of fault conditions and de- MOGL activates related circuitry accordingly. The front-panel provide LEDs indication of the state of these functions. indicator STANDBY Status Colour Temperature controller off. DARK → → Reset via keyswitch, STANDBY Possible faults: •...

  • Page 60: Diode Off / On Indicator

    Appendix B. Troubleshooting B.2 Diode indicator Status Colour Fault → → Reset via switch Possible faults: • switch not up ( SCAN LOCK SCAN • switch not up ( LOCK • Rear interlock disconnected • Laser head interlock disconnected • Laser head cable disconnected •...

  • Page 61: 250 Khz Modulation

    B.3 250 kHz modulation B.3 250 kHz modulation The 250 kHz sine-wave oscillator relies on critical non-linear be- haviour of an electronic component. Due to component drift, the oscillator may cease, and the error signal is then lost. A few small adjustments of trimpots will restore the oscillator.
  • Page 62 Appendix B. Troubleshooting the 2 6 V p-p. 3. Probe test point P7 (near RT8 Amp-D and U28), and adjust RT8 to obtain a 1 0 V peak-peak sine wave. 4. With the rear-panel I trimpot set to maximum (fully clock- wise), probe test point P36 (just to the right of U59) and adjust RT6 Amp-D to obtain a 1 0 V peak-peak sine wave.

  • Page 63: Locking

    B.4 Locking B.4 Locking abs controller provides feedback via three channels each MOGL with a complex servo loop function. A few common problems are addressed here; for more difficult problems, abs will be happy MOGL to work with you to find the best possible solution. B.4.1 does not lock SLOW...
  • Page 64 Appendix B. Troubleshooting B.4.3 does not lock FAST • feedback has wrong polarity. Try reversing the polarity FAST with the front-panel switch. • If the laser frequency is close to a mode hop (i.e. intrinsic diode cavity resonance is half way between two external-cavity longitudnal modes), the current response can be opposite to normal.

  • Page 65: C Using Dbr/Dfb Diodes

    C. Using DBR/DFB diodes DBR (Distributed Bragg Reflector) and DFB (Distributed Feed- Back) diodes offer a compact and robust alternative to s. The ECDL linewidth of DBR and DFB diodes is typically 2 to 3 MHz, and they are very susceptible to external optical feedback, necessitating two or even three stages of Faraday isolator to prevent frequency in- stability.

  • Page 66: Slow Current Feedback

    Appendix C. Using DBR/DFB diodes C.3 Slow current feedback The feedback signal that normally drives the actuator can be DISC coupled to the current feedback, by turning switch 16 ON C.4 Lock saturation Slow drift is normally compensated by the actuator, and hence STACK and current feedback signals only have small range, and...

  • Page 67: D Modulation Coils

    Figure D.1: Vapour cell, Zeeman coil, and primary excitation coil, mounted (available from MOGLabs). D.1 Field requirements Ideally the Zeeman dither coil should produce a frequency shift of about half the peak width, typically a few MHz.

  • Page 68: Coil Impedance

    Appendix D. Modulation coils where is the number of turns per unit length and the current. For wire diameter 0.4 mm, = 2500 m , and the current requirement is only 22 mA/MHz. D.2 Coil impedance However, driving an oscillating current through a coil is problematic because the impedance grows with the frequency.

  • Page 69: Impedance Matching

    D.3 Impedance matching operates at ω = 250 kHz. For a cell of length MOGL 8 cm, 0.4 mm wire, and 20 mA, we find L Wheeler ≈ 650 µH, and = 20 V, and the maximum slew rate is 32 V/µs. does not have that direct output capability.

  • Page 70: Tuning

    Appendix D. Modulation coils equals the inductive impedance. That is, ωL = (D.3.7) ωC ω Using the long-solenoid equation for inductance, (D.3.8) ω µ although in practice we find that the inductance is about half the long-solenoid prediction and hence the capacitance should be dou- bled, typically about 1 to 5 nF.

  • Page 71: Shielding

    D.5 Shielding RBW 1 kHz Marker 1 [T1 ] -30 dBm VBW 30 kHz -41.37 dBm Ref -26 dBm 5 dB SWT 2.5 s 250.000000000 kHz -100 -110 -120 Center 250 kHz 50 kHz/ Span 500 kHz Figure D.3: Coil response acquired using a spectrum analyser with track- ing generator.
  • Page 72 Appendix D. Modulation coils...

  • Page 73: E External Modulators And Injection Current Modulation

    E. External modulators and injection current modulation is designed for locking a laser to an external MOGL reference such as an atomic resonance or an optical cavity. In many cases it is convenient to use the internal modulator driver, and Zee- man modulation of an atomic transition, as described in appendix D.

  • Page 74: Injection Current Modulation

    Appendix E. External modulators and injection current modulation former. Primary and secondary were wound with 10 turns of PVC- insulated hookup wire around a ferrite bead approximately 15 mm diameter. A 500 Ω potentiometer allows control of the modulation amplitude, and a 9 V battery and 100 kΩ potentiometer provide a shift to set the centre modulator frequency.
  • Page 75 75 kHz/ Span 750 kHz Figure E.3: beatnote from two MOGLabs -locked lasers. The 3 dB peak width was 750 Hz with a spectrum analyser RBW setting of 300 Hz. For a 20 s average, the width was about 4 kHz.
  • Page 76 Appendix E. External modulators and injection current modulation...

  • Page 77: F Photodetector

    A number of M4 and 8-32 threaded holes allow mounting in differ- ent configurations to minimise the footprint on an optical bench (see figure F.2). Figure F.1: MOGLabs balanced differential photodetector. Figure F.2: M4 mounting holes are marked with a dimple; others are 8-32.

  • Page 78: Photodiodes

    Appendix F. Photodetector F.1 Photodiodes The standard photodetector uses Si-PIN photodiodes encapsulated in a coloured plastic which transmits in the near-infrared and blocks most room light. The diodes include a lens to reduce the acceptance ◦ angle to ±10 . Unfiltered diodes, and wider acceptance angles, are also available.

  • Page 79: G Laser Head Board

    MOGL provided with abs lasers. MOGL Figure G.1: MOGLabs laser head board showing headers for con- nection of laser diode, piezo actuators, temperature sensor, and head enclosure interlock. G.1 Headboard connectors...

  • Page 80: Dual Piezo Operation

    Appendix G. Laser head board Note only one temperature sensor should be connected. For high bandwidth modulation (see below), the diode should be con- nected to the connector ( ) rather than to the MOLEX Another very small circuit board, to connect directly to the diode, is also available from abs, with connectors.

  • Page 81: Rf Coupling

    G.3 RF coupling and tilt of a diffraction grating, to increase the mode-hop free tuning range. This is the default configuration for Rev. 9.01. For earlier revisions, to activate this mode: • Connect the second STACK • Insert a 0R0 resistor, size 0603, for R602 •...
  • Page 82 Appendix G. Laser head board Figure G.2: MOGLabs laser head board schematic. The mod- ulation low-pass cutoff frequency is determined by C4 and the diode impedance (∼ 50Ω).

  • Page 83: H Feedback Overview

    H. Feedback overview RT6 current Dip 3 dither gain & front panel MOD Current dither enable Rear panel Imod Dither current range Sine ref Gain 250kHz Diode current dither Front panel Mod out Phase adjust Phase 0 − 360° Front panel MOD Dither on/o Demodulator Sine ref...
  • Page 84 Appendix H. Feedback overview Rear panel Sweep frequency Dip 9 External sweep enable Sweep generator Summer Rear panel BNC Front panel or DI-2 Bu er External sweep R113 Scan/Lock Rear panel BNC Front Panel Trigger out (TTL) External Sweep amplitude sweep signal Front panel Frequency...
  • Page 85 Dip 12 Front Panel Bypass AC RT12 Current gain Phase gain Error signal Integrator Phase lead Gain Rear panel Current limit Current Regulator 100uA/V Front panel or DI-3 Display : Current Current control Current Actual & Limit (-) enable ‘FAST’ control Diode Voltage 2.5mA/V...
  • Page 86 Appendix H. Feedback overview...

  • Page 87: I Connector Pinouts

    I. Connector pinouts I.1 Laser WARNING: The connector is a standard LASER DVI-D Dual Link socket as used for consumer digital display devices. It should only be connected to the corresponding abs laser head board. It MOGL supplies the high-voltage signals to drive the laser piezoelectric actuators.

  • Page 88: Photodetector

    Appendix I. Connector pinouts I.2 Photodetector The photodetector is connected via standard 6-pin (FireWire) IEEE-1394 connectors. Note that firewire cables swap pins 3,4 with pins 5,6 so the pinout on the photodetector connector is different to that on the controller. Controller Detector Ground...

  • Page 89: Digital Control

    I.4 Digital control I.4 Digital control HD12 is a 10-pin header which provides access to several impor- tant control signals for locking and for sample-and-hold of the lock- point, as described in section 2.6. The signals are standard compatible, > 2 4 V and <...
  • Page 90 Appendix I. Connector pinouts...

  • Page 91: Pcb Layout

    J. PCB layout...
  • Page 92 Appendix J. PCB layout...

  • Page 93: K 115/230 V Conversion

    K. 115/230 V conversion K.1 Fuse The fuse is a ceramic antisurge, 2.5A, 5x20mm, for example Littlefuse 021502.5MXP. The fuse holder is a red cartridge just above the IEC power inlet and main switch on the rear of the unit (Fig. K.1). Figure K.1: Fuse catridge, showing fuse placement for operation at 230 Vac.
  • Page 94 Appendix K. 115/230 V conversion Figure K.2: To change fuse or voltage, open the fuse cartridge cover with a screwdriver inserted into a small slot at the top of the cover, just above the red voltage indicator. When removing the fuse catridge, insert a screwdriver into the recess at the top of the cartridge;...
  • Page 95 K.2 120/240 V conversion Figure K.4: Bridge (left) and fuse (right) for 230 V. Swap the bridge and fuse when changing voltage, so that the fuse remains on the right-hand side (see below). Figure K.5: Bridge (left) and fuse (right) for 115 V.
  • Page 96 Appendix K. 115/230 V conversion...
  • Page 97 Bibliography [1] C. J. Hawthorn, K. P. Weber, and R. E. Scholten. Littrow config- uration tunable external cavity diode laser with fixed direction output beam. Rev. Sci. Inst., 72(2):4477, 2001. i [2] L. Ricci, M. Weidem¨ u ller, T. Esslinger, A. Hemmerich, C. Zim- mermann, V.

  • Page 98: References

    [10] S. C. Bell, D. M. Heywood, J. D. White, and R. E. Scholten. Laser frequency offset locking using electromagnetically in- duced transparency. Appl. Phys. Lett., 90:171120, 2007. 62 [11] G. C. Bjorklund. Frequency-modulation spectroscopy: new method for measuring weak absorptions and dispersions. Opt.
  • Page 100 2007 – 2015 MOG Laboratories Pty Ltd 18 Boase St, Brunswick VIC 3056, Australia Product specifications and descriptions in this doc- Tel: +61 3 9939 0677 info@moglabs.com ument are subject to change without notice.

This manual is also suitable for:

Dlc102Dlc252Dlc502

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