Your solution for laser diodes and photonics systems | AeroDIODE
Your solution for laser diodes and photonics systems | AeroDIODE
User Manual for AeroDIODE models including: AOM Series Fiber coupled AOM Free Space AOM and RF Drivers, AOM Series, Fiber coupled AOM Free Space AOM and RF Drivers, AOM Free Space AOM and RF Drivers, Space AOM and RF Drivers, RF Drivers, Drivers
Acousto Optic Modulator - SHIPS TODAY - 380 bis 1700 nm - AOM Modulator - Acousto Optics Modulator
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DocumentDocumentUser Manual AOM Series Fiber coupled AOM Free Space AOM & RF Drivers AeroDIODE - Institut d'optique d'Aquitaine - Rue François Mitterrand 33400 Talence - France - Tél.: +33 (0)6 27 69 41 62 www.AeroDIODE.com Contents Revision Sheet............................................................................................................................. 2 1. General information ............................................................................................................... 3 1.1 Definitions ....................................................................................................................... 3 1.2 General warning.............................................................................................................. 3 2. Safety Instructions .................................................................................................................. 4 2.1. AOM Safety instruction................................................................................................... 4 2.2. RF Driver Safety instruction ............................................................................................ 4 2.3. Contact ............................................................................................................................ 5 3. Package Content ..................................................................................................................... 5 4. Absolute Maximum Ratings .................................................................................................... 5 4.1. AOM (Fiber-coupled/Free-space) ................................................................................... 5 4.2. RF Driver.......................................................................................................................... 6 5. Installation .............................................................................................................................. 6 5.1. AOM installation ............................................................................................................. 6 5.1.2. Free-space AOM................................................................................................................ 6 5.2. RF Driver installation....................................................................................................... 7 5.3. How to control the RF power level and the RF frequency ............................................. 9 5.3.1. Frequency measurement :...................................................................................... 9 5.3.2. Max power measurement : .................................................................................. 10 5.3.3. Modulation frequency measurement :................................................................. 11 6. Example of applications ........................................................................................................ 13 6.1. Pulse picking with an AOM ........................................................................................... 13 6.2. 1st order diffraction with a free-space AOM................................................................. 14 6.2.1. Typical insertion losses ......................................................................................... 16 6.2.2. Typical AOM RF tunability..................................................................................... 16 Page 1/16 v1.5 Revision Sheet Release No. V1.0 V1.1 V1.2 V1.3 Date 25/09/2021 11/06/2023 21/07/2023 V1.4 22/11/2023 V1.5 28/03/2024 Author SER SER SER SER MFA LRB/MFA /AMO Revision Description First version Second version Third version highlight the critical RF power level Fourth version highlight the max RF power for the various models Fifth version updated with the free space AOMs Sixth version updated with RF power measurement instructions, dual output AOM, applications. Update Warning and Caution. Disclaimer : Information in this document is subject to change without notice. Copyright © AeroDIODE Bât. IOA, rue François Mitterrand 33400 Talence France www.AeroDIODE.com Page 2/16 v1.5 1. General information Please read this manual carefully. It describes the hazard the user might be exposed to while using the product. It also explains in details how to use the product in the safest and most efficient possible way. The safety of any system incorporating the product is the responsibility of the assembler of the system. Any actions taken by the user that is not clearly described in this user manual might present a risk and is the sole responsibility of said user. This product is to be used in laboratory or industrial tasks, and only by personnel who have followed a training in laser hazard. This product is an OEM device for system integration. It is designed for use as a component (or replacement) part and is thereby exempt from 21 CFR1040.10 and 1040.11 provisions. Make sure it is not put in operation before the machine in which it will be integrated has been declared to be compliant with the relevant requirements of the current directives : · 2006/25/CE (following for example the regulation NF EN 60825-1) (Europe) · 21 CFR1040.10 and 1040.11 provisions (USA) 1.1 Definitions Caution : A "caution" is advised when dealing with hazardous situations, tasks or objects, to avoid material damage or failure. Warning : A "warning" is given for potentially dangerous situation for people which cause them harm or lead to death Note : A note is a complementary piece of advice that must be acknowledged by the user. 1.2 General warning WARNING The compatible laser sources used with the AOM can deliver up to several Watts of coherent LASER radiation. Always wear protective goggles and observe the safety instructions provided by the laser diode supplier when using the AOM and/or AOM driver with your laser source. Caution Do not try to open or remove the cover of the AOM or RF driver modules. Page 3/16 v1.5 Caution Avoid all shocks and strains when handling the AOM Caution Handle the fiber-optic cables with care as it is fragile. Do not bend or pinch it. WARNING Any settings or hardware tinkering that is not described in this user manual or in the usage recommendation may put the user or its environment at risk. WARNING The maintenance and servicing of the AOM should NOT be executed by the end user : only AeroDIODE is able to maintain the AOM. 2. Safety Instructions 2.1. AOM Safety instruction WARNING Not following the safety recommendations and the caution mentioned above can lead to eye damage. 2.2. RF Driver Safety instruction Caution Do not power up the signal output interface when it is open or shorted. Risk of permanent damage. Caution The product should be well grounded, otherwise the performance can be affected. Caution The product is sensitive to ESD. Page 4/16 v1.5 2.3. Contact If you have any question about the AOM module, please contact AeroDIODE : www.aerodiode.com 3. Package Content The AOM modules comes with: · 1 AOM module with 900 µm fiber and 2* FC/APC fiber connectors OR 1 Free-Space AOM with adapted mounting base OR 1 dual output AOM with 900 µm fiber and 3* FC/APC fiber connectors. · A USB Key with the current user manual in pdf The Driver part comes with : · An SMA/SMA cable to connect the RF driver to the AOM · An SMA/BNC cable to connect the RF driver to an AWG · A special cable with Banana plugs to connect to a benchtop power supply 4. Absolute Maximum Ratings 4.1. AOM (Fiber-coupled/Free-space) · Optical power (CW) : refer to the AOM model Datasheet · Storage temperature -40 to +85 · Operating temperature 0 to +60 · Caution : Applying a maximum RF power (voltage) above the maximum efficiency can lead to AOM permanent damage. As a first test level : a maximum RF power below 2W must be securely set. CAUTION : The table below show the various typical and absolute max RF powers : Model (wavelength/RF frequency) 780 / 100 MHz 780 / 200 MHz 850 / 100 MHz 850 / 200 MHz 940 or 1064 / 100 MHz 940 or 1064 / 200 MHz 1310 / 1550 or 1650 / 80 MHz 1310 / 1550 or 1650 / 200 MHz Typical RF power (W) 1 1,5 1.8 2.3 1,8 2,3 2,3 2,3 Absolute Max RF power (W) 2.0 2.0 2.0 2.5 2.0 2,5 2,5 2,5 Page 5/16 v1.5 4.2. RF Driver · Operating voltage: +24V DC · Control signal levels from 0 to +5.5V · Storage temperature -40 to +85 · Operating temperature 0 to +60 5. Installation 5.1. AOM installation 1. Wear safety Googles 2. Wear a proper and working ESD wrist strap; 3. Caution : Set the module on a heat dissipating surface (an optical table works fine). Letting the AOM in air with no dissipating surface leads to overheating and permanent damage. 4. The light can be inserted in any direction. The performance are the same (insertion loss, extinction ratio etc.) 5. Caution : when using another RF driver, The RF power shall not be set over the maximum diffraction efficiency level. A power over 2W can lead to a permanent damage. The RF power must be adjusted progressively from 0 V up to the maximum diffraction level. 5.1.2. Free-space AOM For free-space AOM, a specific mounting plate is provided. This plate has to be screwed to the AOM on one side, and to a M4 optical post on the other side. This would help to mount the AOM onto an optical table (see below). Page 6/16 v1.5 5.2. RF Driver installation The product is dissipated by conducting heat. The product shall be mounted on a metal structure using fixing screws. The mounting surface shall be flat with minimum size and thickness. A certain amount of space should be reserved around and above the product. The product is powered by a DC of + 24V, and the power connector is supplied with a per-centric capacitor; The core of the heart capacitor is connected to the positive power supply, and the grounding sheet of the heart capacitor is connected to the negative pole of the power supply. The characteristic impedance of the product signal output port is 50 . The product receives both external pure analog and/or digital modulation. The adjustment of RF output power is achieved by changing the resistance of a multi-turner : turn clockwise to increase the output power, turn counterclockwise to decrease the output power. 1. Make sure the RF Driver has the correct RF frequency required by the AOM model (model 1 : 100 MHz, model 2 : 200 MHz, model 3 : 80 MHz ; model 4 : 200 MHz). 2. Make sure the RF Driver model is the one you need (TTL input or Analog input). 3. Connect the RF driver to the AOM with the SMA cable. If you use the modular model RFAOM-TA-200, set the S1-S4 switch to the proper configuration (see below) Caution : Always connect the RF driver to the AOM before powering, using the RF driver without a charge could lead to a permanent damage. 4. Caution : Place the module on a heat dissipating surface (an optical table works fine). Letting the RF driver in air with no dissipating surface leads to overheating and permanent damage. 5. Connect a 24V >0.5A power supply to the RF driver 6. Caution : The RF power shall not be set over the maximum diffraction efficiency level. A power over 2W rapidly leads to a permanent damage. The RF drivers power level (little screw) is normally set in a safe area allowing a correct diffraction efficiency. If ever it is adjusted, this must be done progressively from 0 V up to the maximum diffraction level. If necessary, you can monitor the RF power level using a scope and a 20 dB attenuator (because of the strong voltage amplitude), see part 5.3. 7. Connect the trigger signal and make sure you apply the good electric signal : · TTL 5V-50 Ohm for standard RF-AOM-T-xxx model, · Analog 0-5V signal for RF-AOM-A-xxx · Any signal (0-5V or 0.1V) for the modular RFAOM-TA-200 model 8. If you need to optimize the insertion loss, apply a small optical CW signal at the proper wavelength and apply a CW trigger signal to the RF Driver. Use a screwdriver (Ø 3mm Multiturn) to adjust the RF power to get maximum optical power at the output of the AOM. Page 7/16 v1.5 Figure 1 Example of integration of standard model (either RF_AOM-T-xxx or RF_AOM-A-xxx ) at either 80, 100 or 200 MHz : Figure 2 : Model RFAOM-TA-200 S1-S4 settings RFAOM-TA-200 Configuration switch : · S1Down : TTL high ; Up : TTL low input signal configuration setting · S2Down : TTL mode active ; Up : TTL mode disabled · S3Down : Analog input range : 0 -1V ; Up : Analog input range 0 - 5V. · S4Down : Analog mode active ; Up : Analog mode disabled Page 8/16 v1.5 5.3. How to control the RF power level and the RF frequency For this setup, you need : - An oscilloscope (50 Ohm impedance input, bandwidth tuned to maximum) - A 20dB attenuator - A RF driver - An AWG (or AeroDIODE TOMBAK) - A 24 VDC power supply - 2 SMA/SMA or SMA/BNC cables (according to your AWG and scope) Oscilloscope 20dB attenuator « RF out to AOM » output RF driver AWG / Tombak « Sync In » input 5.3.1. Frequency measurement : - Adjust your AWG parameter to get a +5V offset (50 Ohm impedance) signal. - Connect your SMA/SMA cable or SMA/BNC cable between the "RF out to AOM" output from the driver to the 20 dB attenuator which is connected to one of the oscilloscope channels. - Connect the power supply to your RF driver Page 9/16 v1.5 - Turn the 24VDC power supply on (only when the RF signal is connected to the oscilloscope through the attenuator!). - Turn your AWG signal on (only when the 24VDC power supply is turned on !). - Observe the RF frequency modulation (80 MHz, 100 MHz, 200 MHz or else if custom. Figure 3 : Monitoring of the RF frequency 5.3.2. Max power measurement : Keep the same setup. Display the RMS voltage on your oscilloscope. Figure 4 : Monitoring of the RMS voltage of the RF signal Page 10/16 v1.5 You can calculate the RF power by applying the following formula: = ײ For a voltage of 1.19 , the output power is of 2.8 W. If the measured power differs from what's indicated in the test repot, you can adjust it rotating clockwise or counter-clockwise with a screwdriver (Ø 3mm Multiturn) the screw which is located below the "RF level adjust" label in the RF driver. 5.3.3. Modulation frequency measurement : - If the RF driver is analogic : send a 0-5 V (50 Ohm impedance) sinus-shaped signal of 10 kHz into the "Sync In" input port from the RF driver. Figure 5 : Monitoring of the modulation trigging analog signal Page 11/16 v1.5 - If the RF driver is numeric (TTL) : send a 0 V-5 V (50 Ohm impedance) square-shaped of 10kHz into the "Sync In" input port from the RF driver. Figure 6 : Monitoring of the modulation trigging TTL signal - If the RF driver is both analog and numeric (TTL) : refer to the switch position (part 5.2) and do both previous measurements. Figure 7 RF output power variation with applied modulation voltage into analog or numeric RF driver Page 12/16 v1.5 6. Example of applications 6.1. Pulse picking with an AOM To setup your pulse picker, you need : - A fiber-coupled or free-space AOM - A RF driver - An AeroDIODE TOMBAK pulse-picker synchronization tool - A laser source (with a triggering frequency output or a photodetector to detect the pulse frequency) - A photodetector - SMA/SMA and SMA/BNC cables - An oscilloscope (if necessary) The synoptic diagram is as follows: Pulsed laser AOM Photodiode Oscilloscope Frequency Trigger Out Pulse In Pulse Out Tombak Pulse Picker RF out to AOM RF driver Sync In - The Tombak Pulse Picker divides the input trigging frequency and send the generated signal to the "Sync In" RF driver input. (Note that the Tombak Pulse picker synchronization allows to configure several pulse-picking modes, including some modes with external low frequency triggering). See this product web page for more information. - Adjust the pulse width and the delay of the generated signal to get a better extinction ratio between each pulse. Page 13/16 v1.5 Figure 8 Pulse-picking measurement result. 6.2. 1st order diffraction with a free-space AOM To setup your 1st order diffraction, you need : - A free-space AOM with mounting adapter - An optical post or a specific translation or tilted stage. - A RF driver - An AWG (or AeroDIODE Tombak) - A laser source (collimated or with an external collimator) - A photodetector - SMA/SMA and SMA/BNC cables - An oscilloscope or powermeter (if necessary) The synoptic diagram is as follows : Laser Free-space AOM Pulse Out AWG (or Tombak) RF out to AOM RF driver Sync In Photodiode Page 14/16 v1.5 Oscilloscope - Make sure the AOM input beam diameter is in the range of the free-space AOM acceptable beam diameter. This will help to get the better diffraction efficiency. - Move the free-space AOM in order to focus at best the input beam into the AOM slot. - If your setup is adjusted, you should see the zero order (non-diffracted beam) and the first order (diffracted). If necessary, translate the AOM to get the highest power/signal at the AOM output. Figure 9 Diffraction principle by the AOM (acousto-optic effect) Diffraction angle: The diffraction Angle can be calculated using the following formula : = *f/V · : diffraction angle (in mrad) ; · : wavelength (in nm) · f : RF frequency (in MHz) · V=velocity of sound =4200 Example : 635 nm , 200 MHz RF frequency => =30 mrad Page 15/16 v1.5 6.2.1. Typical insertion losses Figure 10 Typical insertion losses as a function of the input wavelength into AOM various models 6.2.2. Typical AOM RF tunability Figure 11 AOM RF tunability for each of the AOM RF frequencies Page 16/16 v1.5