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Message ID: 2392     Entry time: Mon Aug 12 12:09:00 2019
Author: Nathan Holland 
Type: Summary 
Category: 2micronLasers 
Subject: Adjusting the Voltage/Frequency Offset on the Brimrose AOM Driver. 

The 80 MHz brimrose AOM driver, which came with the AOM, can actually drive between 75 MHz and 85 MHz. It has an input port, which accepts between 0V and 10V, for altering the frequency.

 

Previously, before Friday 2019-08-09, I had set the offset to + 5V, using a signal generator because that was what was available in the QIL lab. The signal generator, for some unclear reason, had then moved this offset to +4.4 V, when plugged into the AOM driver. Attachment 1 shows a power spectrum, from the BB PD, One notices a large peak negatively detuned from the 80 MHz signal frequency. Attachement 2 shows a zoom in, around 70 MHz, revealing this peak to be two peaks, one near 78 MHz, and another smaller one near 79 MHz.

I decided to adjust the voltage, input to the frequency port, to minimise the RF sidebands I observed. The results of this adjustment can be seen in attachments 3, and 4. Notice that there no observable sidebands. This was achieved with an offset of 4.52V.

 

Attachement 5 is the manual for the AOM, and its driver. (Removed by KA)

Attachment 1: 2um_MachZehnder_wide_PowerSpectrum_Screenshot.png  326 kB  Uploaded Mon Aug 12 13:14:12 2019  | Hide | Hide all | Show all
2um_MachZehnder_wide_PowerSpectrum_Screenshot.png
Attachment 2: 2um_MachZehnder_narrow_PowerSpectrum_Screenshot.png  335 kB  Uploaded Mon Aug 12 13:14:35 2019  | Hide | Hide all | Show all
2um_MachZehnder_narrow_PowerSpectrum_Screenshot.png
Attachment 3: 2um_MachZehnder_wide_PowerSpectrum_adjusted_Screenshot.png  322 kB  Uploaded Mon Aug 12 13:26:14 2019  | Show | Hide all | Show all
Attachment 4: 2um_MachZehnder_narrow_PowerSpectrum_adjusted_Screenshot.png  328 kB  Uploaded Mon Aug 12 13:26:27 2019  | Hide | Hide all | Show all
2um_MachZehnder_narrow_PowerSpectrum_adjusted_Screenshot.png
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