These are the measurements for estimating the amplitude of the signal recorded in the CDS when a known amount of modulated light is incident on the photodiode.
I mounted the PD characterisation setup onto a small breadboard which could then be placed close AP table. I then placed position markers for REFL165 on the AP table before moving it onto my small breadboard. The AM laser was driven by an RF function generator (Fluke 6061A) at a frequency of 165.98866 MHz, which is 102 Hz offset from the 165MHz LO. The power level was set at -45dBm. This power level was chosen since anything higher would have saturated the AntiAliasing Whitening Filters. The counts in the CDS were converted to voltage using the ADC resolution = 20V per 2^16 counts.
When the 166MHz power is decreased by a factor of 2 the amplitude of 102Hz wave recorded in CDS goes down by sqrt(2) as expected. The RF AM power incident on the REFL165 was estimated to be 0.011mW(rms) (case #1 in the above table) using the DC power ratio and using the transimpedance of the 1611 BBPD to be 700 Ohms. This produces a 171 mV amplitude wave at 102 Hz. I then stepped down the power by factor of 2 and repeated the measurement.
(These numbers however are not agreeing with the power incident on REFL165 if we assume its transimpedance to be 12500. It will take a bit more effort to make all the numbers agree. Will try again tomorrow)
Here is a picture of the small black breadboard on which I have put together the PD characterisation setup. It would be great if we can retain this portable set up as it is, since we keep reusing it every couple of weeks. It would be convenient if we can fiber couple the path to the PD under test with a 2m long fiber. Then we will not have to remove the PD from the optical table while testing it.