Related Manuals for MOGlabs FZW600
Summary of Contents for MOGlabs FZW600
- Page 1 Fizeau Wavemeter and Fibre Switcher FZW600, FSW4, FSW8 Version 0.3.2: Rev 2 hardware, firmware v0.9.3, mogfzw v1.4.1...
- Page 2 MOGL abs. Contact For further information, please contact: MOG Laboratories P/L MOGLabs USA LLC 49 University St 419 14th St Carlton VIC 3053 Huntingdon PA 16652 AUSTRALIA +61 3 9939 0677 +1 814 251 4363 info@moglabs.com...
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Page 3: Table Of Contents
Contents Getting started 1 Introduction 1.1 How it works ..... . . 1.2 Features ......2 Connections and controls 2.1 Front panel interface . - Page 4 Contents 6 Optical switch 6.1 Overview ......6.2 Operation ......6.3 Optical bands .
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Page 5: Getting Started
Getting started 1. Connect to +5 V power via the port or the barrel jack. When powering with , it is important that the host can supply up to 600 mA. Some older computers may detect this as a short-circuit and power down the device; -3.0 compliant hubs are recommended. - Page 6 Getting started Figure 1: Both the built-in wavemeter display (left) and host software (right) provide saturation indicators that measure the optical power reach- ing the detector. That’s it: with a coupled fibre you should be able to read the wave- length within two seconds of power-on.
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Page 7: Introduction
1. Introduction 1.1 How it works is a high-precision device that measures laser wavelengths using a set of Fizeau interferometers. A Fizeau interferometer is formed by two planar surfaces with a small wedge angle between them, which generates spatially-varying interference fringes as the optical path length changes (Fig. -
Page 8: Features
Chapter 1. Introduction 1.2 Features MOGL has no moving parts, and very high sensitivity semiconductor imaging, enabling high measurement speed (up to 350 per second) and measurement of pulsed sources with only a few microwatts of light. Long lifetime is assured as there are no mechanical parts to wear out. The etalons are optically-contacted fused silica, with a low thermal expansion coefficient, making the instrument incredibly robust, reli- able, and stable. -
Page 9: Connections And Controls
This allows autonomous usage of the wavemeter indepen- dently of a computer. Figure 2.1: MOGLabs front panel layout. The buttons are arranged with up, down, left and right buttons, and an additional OK button in the centre. - Page 10 Chapter 2. Connections and controls indicators display the current state of the device, as listed in the table below. Indicator Colour Status ÿ Off Unit is powered off Green Normal operation Blue Firmware update mode Off No measurement in progress Green Normal operation Yellow...
- Page 11 2.1 Front panel interface Within the menu system, the up and down buttons control the se- lected item. Pressing OK on a selected item activates it to allows editing the value, entering the submenu, or executing the command. Pressing the left button returns to the previous menu, or exits the menu system.
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Page 12: Rear Panel Controls And Connections
Chapter 2. Connections and controls 2.2 Rear panel controls and connections TRIG +9-30V Figure 2.4: MOGLabs Rev4 rear panel layout. From left to right, the features of the rear panel (Figure 2.4) are: Power switch Switches the unit on/off. DC supply 2.1mm centre-positive barrel-jack connector for supplying power the... -
Page 13: User Interface
3. User interface 3.1 Device UI includes an integrated user interface for operating the wavemeter independently of a host computer. The primary display shows the currently measured wavelength (Figure 3.1) in units that can be selected via the up/down buttons. Figure 3.1: Primary wavelength display showing the measured wave- length, saturation and contrast, as well as the device address. -
Page 14: Web Ui
Chapter 3. User interface Figure 3.2: Diagnostic modes of the device UI: etalon display (left) permits verification of fringe quality, and time-series display (right) shows variation in the measured wavelength over time. 3.2 Web UI includes a simple web interface for monitoring the de- vice remotely through a web browser, such as using a smartphone. -
Page 15: Software Ui
3.3 Software UI In environments where embedded devices running web servers con- stitute a security concern, the web interface can be disabled using ETH,WEB,0 the command or through the Menu System by selecting Options→Ethernet→Web server→OFF. 3.3 Software UI A fully-featured control and diagnostic program suite for Windows™ operating systems is available from the MOGL abs website. - Page 16 Chapter 3. User interface The wavelength display box has selectable units, and can be resized to increase the font size and make the measurement easier to read from a distance. The exposure controls on the left-hand side include a scale bar showing the optical saturation.
- Page 17 3.3 Software UI Figure 3.5: The time-series window shows how the wavelength measure- ment is changing over time, for measuring drift. The graph displays Du- ration seconds of data, with a datapoint collected every Interval seconds. When Averaging is enabled, the wavelength measurements during each interval are averaged to enhance the measurement precision.
- Page 18 Chapter 3. User interface Figure 3.6: The can be used to measure the mode-hop free scan- range of a laser. Setting the Interval to zero ensures measurements are recorded as rapidly as possible. The measurement rante, measurement mean, standard deviation and peak-to-peak range are shown in the status bar at the bottom.
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Page 19: Operation
4. Operation 4.1 Fringe identification and optimisation The host software includes a prominent display of the interference fringes used to compute the laser wavelength. Understanding the fringe structure is important in ensuring that the wavelength mea- surement is accurate. The two primary causes of reduced measure- ment reliability are laser multi-moding, and poor spatial profile of the light emitted by the fibre. - Page 20 Chapter 4. Operation Figure 4.2: A multimoding laser might only be evident in one of the inter- ference patterns. In some circumstances this will be clear from an obvious change in fringe spacing (left), whereas at other times the secondary peaks might be smaller amplitude (right).
- Page 21 4.1 Fringe identification and optimisation Figure 4.3: Example fringes measured with a 62 5 m-core fibre demon- strating envelope structure that causes measurement bias (left). Adjusting the input coupler alignment can give more uniform fringe heights (right) and more reliable measurement. Figure 4.4: Examples of fringes measured with a 200 m-core fibre.
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Page 22: Auto-Exposure Algorithm
Chapter 4. Operation In this scenario the unmeasurable etalons are ignored, and it may still be possible to extract a wavelength estimate with vastly reduced accuracy (∼ 20 GHz uncertainty). In some applications this estimate may be sufficient, but smaller core fibres are strongly recommended. 4.2 Auto-exposure algorithm has an auto-exposure algorithm that rapidly adjusts the exposure time to match the intensity of the incident beam to prevent... -
Page 23: Externally Triggered Mode
4.5 Externally triggered mode by some pixels and not others. Enabling pulsed mode changes the camera to a global shutter configuration to prevent this scenario from ocurring. Note however that global shutter mode is not recommended for lasers as it tends to result in distortion from an effective over- exposure towards the bottom of the imaging sensor. -
Page 24: Calibration Adjustment
Chapter 4. Operation –2 –1 Averaging �me, s Figure 4.5: Measurement of the modified Allan deviation of the mea- suring a locked laser, demonstrating that substantially improved precision can be achieved with averaging. For increasing time (Figure 4.6) the uncertainty grows, depending on environmental changes in temperature and pressuer. - Page 25 4.7 Calibration adjustment Averaging �me, s Figure 4.6: For longer times, the Allan deviation increases, in this case showing a dip at around one day, related to variations in the lab temper- ature. variety of broadband effects. The does not include an internal calibration source because the inherent stability of the across the full wavelength range is better than the accuracy of compact...
- Page 26 Chapter 4. Operation Figure 4.7: The recalibration window of the host software allows correction of the device calibration using a known reference. A standard reference can be selected from the dropdown box, or a custom reference frequency can be entered. MEAS,CORRECT tion can also be applied programmatically using the command.
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Page 27: Pid Locking
5. PID locking can output an analogue signal on the connector (V 2 5 to +2 5 V). That signal can be a fixed value or a control signal that attempts to drive the wavelength of a laser towards a set wavelength. -
Page 28: Using With Mogl Abs Dlc Laser Controller
Figure 5.1: Stabilising a laser frequency with the . The output of the should be connected to the SWEEP/PZT input on the rear of the MOGLabs controller. 5.2 PID parameters feedback signal is calculated on the device, but the param- eters are most easily controlled using mogfzw while watching a plot of the wavelength against time using the time-series window. - Page 29 5.2 PID parameters Figure 5.2: Interactive window for adjusting the constants, including display of the instantaneous error value (in MHz) and the output value (in Volts) for diagnostic purposes. proximately the inverse of the frequeny response of the laser and controller.
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Page 30: Integrator Windup
Chapter 5. PID locking 5.2.1 PID commands PID,KP gains can also be set using and similar commands as in the example script below. # define the desired lock point (in THz) PID,SET,384.22924169 # set the gain to 10 V/GHz PID,GAIN,10 # define the PID gains PID,KP,0 PID,KI,1... -
Page 31: Examples
5.4 Examples long time lag in the response, or prevent the servo controller from ever reaching stable equilibrium. The solution is to stop integrating when the integrator reaches the saturation limit. For MOGL controllers, set V = 2 5, V = 0. - Page 32 Chapter 5. PID locking 5.4.2 Wavelength stabilisation To control the laser wavelength, the output signal should be con- nected to the frequency control input of the laser, usually a piezo control, as in figure 5.1. Set the laser close to the desired wave- length, and click on Enable PID.
- Page 33 5.4 Examples Figure 5.4: Time series measurement of the wavelength when is en- abled at about 8 s. The setpoint is changed at around 20 s and again at 48 s.
- Page 34 Chapter 5. PID locking Figure 5.5: The G gain has been increased to 10 V/GHz, leading to much faster tracking of changes to the setpoint at each of the steps.
- Page 35 5.4 Examples Figure 5.6: Fluctuations in the measured laser frequency when locked. These fluctuations are at the limit of the measurement of the position of the longest etalon fringes: a few MHz in a fringe spacing of 7500 MHz.
- Page 36 Chapter 5. PID locking...
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Page 37: Optical Switch
6. Optical switch 6.1 Overview FSW4 FSW8 are optional 4- and 8-channel optical multi- plexors (switches) that integrate with the , allowing a single wavemeter to be used for monitoring or feedback of up to 8 lasers. The optical switch is only available with -connectorisation. -
Page 38: Operation
Chapter 6. Optical switch Figure 6.2: FSW4 (left) and FSW8 (right) optical switches. The front- panels (top) have fibre inputs and indicators, while the back-panels (bottom) have outputs for monitoring and control. The front-panel buttons cycle between the input fibres. 6.2 Operation FSW4 FSW8... - Page 39 6.3 Optical bands Band Wavelength Range 400 nm 400 – 600 nm 600 nm 500 – 900 nm 1100 nm 800 – 1100 nm Selected middle wavelengths, and ports 3 and 4 for longer wavelengths. The commands would then be as follows: OPTSW,copy,1,0 copy port 1, band 0 to band 3 for blue OPTSW,copy,2,1...
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Page 40: Mogfzw Switch Ui
Chapter 6. Optical switch mirror settings will be used. mogfsw can be found on the MOGL support website for the wavemeter. Figure 6.3: mogfsw allows adjustment of the MEMS mirrors to optimise throughput for a given wavelength for each fibre input port. 6.4 mogfzw switch UI When connecting to an that has an optical switch attached,... - Page 41 6.4 mogfzw switch UI Figure 6.4: The Switch/Bands menu item allows selection of a different optical band for each fibre input port. Figure 6.5: The Switch/Autostep menu option allows enabling auto- increment of the fibre channel, with fixed time delay at each channel.
- Page 42 Chapter 6. Optical switch...
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Page 43: A Specifications
A. Specifications Parameter Specification Accuracy Measurement range 400 – 1100 nm <600 MHz Absolute accuracy Measurement precision 10 MHz (full-speed), 1 MHz (100-sample average) Minimum optical power 10 W (350 meas/s), 100 nW (10 meas/s) Maximum optical power 10 mW Exposure time 100 s to 1 s Measurement rate... - Page 44 Appendix A. Specifications Parameter Specification Interface Ethernet 10/100 RJ45 USB2.0 device with USB-B plug Optical input FC/PC FC/APC as labelled on device Control software Integrated on-device menu system Windows™ software suite Integrated web server python, MATLAB, LabVIEW Language bindings Mechanical W×H×D = 146 ×...
- Page 45 1050 1150 Wavelength (nm) Figure A.1: Typical detector responsivity. Power (µW) 522 nm 780 nm 1095 nm Table A.3: Exposure time (in milliseconds) for different wavelengths.
- Page 46 Appendix A. Specifications...
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Page 47: B Firmware Updates
B. Firmware updates From time to time, MOGL abs will release updates to the device firmware which improve the device functionality. This section con- tains instructions on how to apply firmware updates to your device using the “Firmware Update Tool” available from the MOGL abs web- site as part of the host software suite. - Page 48 Appendix B. Firmware updates Figure B.1: The firmware update application connected to a unit, showing the device serial number (1) and current firmware versions (2). Click the Select button (3) to open a firmware package for upload. Figure B.2: The firmware update application with a loaded package. The versions running on the device are compared against the selected package, in this instance showing that an update is available for the IAP (yellow) and the other components are up-to-date (green).
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Page 49: C Command Language
Please note: The command language is being continuously updated across firmware releases to improve functionality and add features. When upgrading firmware, please refer to the most recent version of the manual available at http://www.moglabs.com Some commands accept values with units. The following units are recognised for returning measurements or defining setpoints:... -
Page 50: Display Settings
Appendix C. Command language C.2 Display settings CONTRAST DISP,CONTRAST[,val] Sets the contrast of the display, which is either a percentage value, or an integer between 0 (off) and 15 (full brightness). SLEEP DISP,SLEEP[,val] Sets the sleep timer of the display, which is the time in seconds after the last button press that the display is dimmed. -
Page 51: Camera Settings
C.4 Camera settings PULSED MEAS,PULSED[,onoff] Enable or disable “pulsed” measurement mode (see §4.4). TRIG MEAS,TRIG[,onoff] Enable or disable externally triggered mode, where a measurement will only occur when the associated rear-panel SMA input is low SOFTWARE (see §4.5). The special argument keyword will generate a software trigger. -
Page 52: Optical Switch
Appendix C. Command language CAM,EXP[,value] value value Set/query the camera exposure time to milliseconds. If value is specified, the auto-exposure algorithm is disabled unless AUTO the string “ ”. MAXEXP CAM,MAXEXP[,value] Set/query the maximum permitted exposure time for the auto-expose algorithm in milliseconds. -
Page 53: Control Voltage Out And Pid
C.6 Control voltage out and PID change the band, provide an integer (0 to 3) argument, for exam- OPTSW,BAND,3 . Note that the mirror positions will not MEMS change to the new values until the input port is selected with an OPTSW,set command. - Page 54 Appendix C. Command language OFFSET PID,OFFSET[,val] Set/query the constant DC offset on the analogue output, in volts. PID,MIN[,val] Set/query the minimum output voltage of the PID controller. PID,MAX[,val] Set/query the maximum output voltage of the PID controller. VALUE PID,VALUE Returns the current output voltage of the controller for monitor- ing purposes.
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Page 55: D Communications
The python and LabVIEW bindings provided take care of buffering and error checking automatically. The MOGLabs Commander application (mogcmd) is available as part of the mogfzw package and provides a convenient interface for send- ing commands and receiving responses (Figure D.1). - Page 56 Appendix D. Communications Figure D.1: The mogcmd application, showing successful and unsuccessful commands and queries. D.2.1 Changing IP address Depending on your network settings you may need to manually set address. This is most easily done via the front-panel interface as detailed below.
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Page 57: Usb
D.3 USB D.3 USB can be directly connected to a host computer using a USB cable. The device will appear as a Virtual port, which behaves like an connection. The required RS232 STM32 Virtual COM Port Driver ) device driver for the Windows operating system is available from the MOGL... - Page 58 Appendix D. Communications D.3.1 USB driver If you do not see a virtual COM port under Ports in the Device Manager then manually install the driver, which is available from the MOGL abs website. More detailed instructions are also available on the website. 1.
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Page 59: E Dimensions And Pcb
E. Dimensions and PCB TRIG +9-30V Figure E.1: FZW chassis dimensions. - Page 60 Appendix E. Dimensions and PCB Figure E.2: FSW fibre switch dimensions.
- Page 61 P2 FSW SWITCH C104 P1 SENSOR C108 TRIG C109 C110 C111 C113 C114 Ethernet C115 C116 C118 C117 C119 C120 C121 JTAG C124 C125 C126 C128 C127 C130 C129 DC 9 - 36V C138 C137 C139 C140 R104 R107 C133 C134 P9 DISPLAY Power...
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Page 62: Internal Connectors
E.1 Internal connectors +5 V Clock Data Figure E.4: P2 connector on main , connects to fibre switch. Clock Ready MISO MOSI +5 V +24 V Figure E.5: P10 connector on main , for serial communications and MOGLabs beam profiler. - Page 64 MOG Laboratories Pty Ltd © 2017 – 2021 49 University St, Carlton VIC 3053, Australia Product specifications and descriptions in this doc- Tel: +61 3 9939 0677 info@moglabs.com ument are subject to change without notice.
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