1. Manuals
  2. Brands
  3. MOGlabs Manuals
  4. Measuring Instruments
  5. FZW600
  6. Manual

MOGlabs FZW600 Manual

Fizeau wavemeter
Hide thumbs Also See for FZW600:
Table of Contents

Advertisement

Quick Links

Download this manual
Fizeau Wavemeter
FZW600
Version 0.1.2, Rev 2 hardware

Advertisement

Table of Contents
loading
Need help?

Need help?

Do you have a question about the FZW600 and is the answer not in the manual?

Questions and answers

Related Manuals for MOGlabs FZW600

Summary of Contents for MOGlabs FZW600

  • Page 1 Fizeau Wavemeter FZW600 Version 0.1.2, Rev 2 hardware...
  • 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...

  • 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 5.4 Simultaneous PID ....A Specifications B Firmware updates C Command language C.1 General functions ..... C.2 Display settings .

  • 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 rea- ching the detector. periodically inspect the measured interference fringes for correct structure (§4.1) to ensure reliable measurement. Typically the will reach thermal equilibrium and full accuracy within 15 minutes of being turned on.

  • 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 as a “directional pad” 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.

  • Page 12: Rear Panel Controls And Connections

    Chapter 2. Connections and controls 2.2 Rear panel controls and connections Figure 2.4: MOGLabs Rev3 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 unit.

  • Page 13: User Interface

    3. User interface 3.1 On-board UI includes an integrated user interface for operating the wa- vemeter 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 on-board 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 device 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 Most of the user interface is dedicated to displaying the etalon fringes, which are important for measurement diagnostics (see §4.1). 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.
  • Page 17 3.3 Software UI Figure 3.5: The time-series window shows how the wavelength measu- rement is changing over time, for measuring drift. The graph displays Duration seconds of data, with a datapoint collected every Interval se- conds. 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: When configured for maximum measurement speed, the can be used to measure the mode-hop free scan-range of a laser. Set- ting the Interval to zero ensures measurements are recorded as rapidly as possible, as indicated by the label in the bottom left.
  • Page 19 3.3 Software UI 3.3.3 PID configuration The application also includes a window for adjusting the constants used for the control loop (§4.7). This provides a convenient interface for optimising the gain values, and verifying the state of the control loop. When the control loop has saturated at one of its limits, the box will be highlighted in magenta.
  • Page 20 Chapter 3. User interface...

  • Page 21: 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 22 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 23 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.

  • Page 24: 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 25: Pulsed Laser Measurement

    4.4 Pulsed laser measurement These two options can be enabled simultaneously to achieve the hig- hest possible measurement rate (> 1200 meas/s for short exposure times). 4.4 Pulsed laser measurement uses an electronic rolling shutter when reading out the camera to ensure each pixel in the camera is subjected to the laser for an identical exposure time.

  • Page 26: Measurement Averaging

    Chapter 4. Operation 4.6 Measurement averaging is capable of several hundred wavelength measurements per second, which can provide valuable realtime feedback when tu- ning lasers. Alternatively, these measurements can be automatically averaged to produce higher precision measurements at a slower rate. The Allan deviation is a useful measure of the improvement achieved by increased averaging, as the influence of measurement noise is reduced but the influence of drift increases.

  • Page 27: Pid Control

    4.7 PID control Note that operating the in environments with poor ambient temperature control may experience much more rapid drift, and the benefit of data averaging is greatly reduced. 4.7 PID control includes an output that provides an analog voltage V ( ) that can be used for locking a laser at an arbitrary wavelength typically by feeding back to the piezo through the laser controller.

  • Page 28: Calibration Adjustment

    Chapter 4. Operation # set the output range to be 0 2.5V centred at 1.25V PID,MIN,0 PID,MAX,2.5 PID,OFFSET,1.25 # activate the PID PID,ENABLE Listing 4.1: Example script to configure the controller The front-panel interface includes a multi-colour which indicates the status of the lock at a glance. The indicator is green when the lock is stable, yellow when the lock is engaged but the error signal has not converged to zero, and red when the output has saturated indicating the lock has failed (see also §2.1).
  • Page 29 4.8 Calibration adjustment Figure 4.6: 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. known laser frequency in THz.
  • Page 30 Chapter 4. Operation...

  • Page 31: Optical Switcher

    5. Optical switcher 5.1 Overview FSW4 FSW8 are optional extra components that integrate with the that provide 4- or 8-channels of optical multiplexing, allowing a single wavemeter to be used for monitoring or feedback of up to 8 lasers (Figure 5.1). The optical switcher is only available with FC/APC -connectorisation.

  • Page 32: Operation

    Chapter 5. Optical switcher the output fiber is not accidentally sheered as it could break. 5.2 Operation FSW4 FSW8 contain a MEMS mirror arrangement that 5.3 Software UI When connecting to a that has an optical switcher attached, the interface will show a tabbed view for the different switcher inputs. Names can be assigned to the inputs by double-clicking the tabs.

  • Page 33: A Specifications

    A. Specifications Specification Parameter Accuracy 400 – 1100 nm Measurement range <600 MHz Absolute accuracy 10 MHz (full-speed), Measurement precision 1 MHz (100-sample average) 500 W (300 meas/s), Minimum optical power 10 W (100 meas/s), 100 nW (10 meas/s) 10 mW Maximum optical power 100 s to 1 s Exposure time...
  • Page 34 Appendix A. Specifications Specification Parameter Interface 10/100 RJ45 Ethernet USB2.0 device with USB-B plug FC/PC FC/APC as labelled on device Optical input Integrated on-device menu system Control software Windows software suite Integrated web server Examples provided for python, MATLAB, Language bindings LabVIEW Mechanical W×H×D = 146 ×...
  • Page 35 1050 1150 Wavelength (nm) Figure A.1: Typical detector responsivity.
  • Page 36 Appendix A. Specifications...

  • Page 37: B Firmware Updates

    B. Firmware updates From time to time, MOGL abs will release updates to the device firm- ware which improve the device functionality. This section contains instructions on how to apply firmware updates to your device using the “Firmware Update Tool” available from the MOGL abs website as part of the host software suite.
  • Page 38 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).

  • Page 39: 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 40: 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 41: 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 (see §4.5). The special argument keyword SOFTWARE will generate a software trigger.

  • Page 42: 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 43: Pid Control

    C.6 PID control C.6 PID control ENABLE PID,ENABLE Activate the controller, producing the control voltage on the output. DISABLE PID,DISABLE Deactivate the controller, setting the output voltage to 0 V. STATUS PID,STATUS Returns the current status of the PID controller. SETPOINT PID,SET[,value] controller setpoint frequency, in THz.
  • Page 44 Appendix C. Command language...

  • Page 45: 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 sen- ding commands and receiving responses (Figure D.1).
  • Page 46 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.

  • Page 47: 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 48 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.

  • Page 49: E Dimensions

    E. Dimensions...
  • Page 52 2017 – 2020 MOG Laboratories Pty Ltd 49 University St, Carlton VIC 3053, Australia Product specifications and descriptions in this do- Tel: +61 3 9939 0677 info@moglabs.com cument are subject to change without notice.

Table of Contents