frilance
Member level 1
Hello fellas,
I'm performing some measuremennts with a laser diode, testing the spatial response of a photodiode. Since my measurements are not as accurate as I would like them to be, I want to use a power stabilization system to achieve some improvement. The thing is that some devices are already available because one person did this before me. Unfortunetly, he didn't leave much information about the circuit , and I prefer to understand it before I use it.
In order to get this power stabilization, a beam splitter is used to get a second beam which is monitored by an auxiliar photodiode. Then, the output of this photodiode is used as the input of this circuit I'm talking about, processed through what-are-supposed-to-be integrators, in order to obtain a signal which could feed the original Laser Diode Driver and get rid (partially) of the laser fluctuations. The problem is I can't completely understand this circuit, and I'm not sure what kind of signal I'm supposed to get at the output.
Could you please help me out with this?
Here there is the schematic of the circuit I'm talking about:
Thank you so much in advance.
Kind regards.
PS. This may help:
- The EpMon just seems a way to monitor the auxiliar PD output, but I still don't know what 'Mod In' is supposed to be.
- C11 and R18 are missing in the real circuit (open circuit I mean). I think the rest of the components are there.
I'm performing some measuremennts with a laser diode, testing the spatial response of a photodiode. Since my measurements are not as accurate as I would like them to be, I want to use a power stabilization system to achieve some improvement. The thing is that some devices are already available because one person did this before me. Unfortunetly, he didn't leave much information about the circuit , and I prefer to understand it before I use it.
In order to get this power stabilization, a beam splitter is used to get a second beam which is monitored by an auxiliar photodiode. Then, the output of this photodiode is used as the input of this circuit I'm talking about, processed through what-are-supposed-to-be integrators, in order to obtain a signal which could feed the original Laser Diode Driver and get rid (partially) of the laser fluctuations. The problem is I can't completely understand this circuit, and I'm not sure what kind of signal I'm supposed to get at the output.
Could you please help me out with this?
Here there is the schematic of the circuit I'm talking about:
Thank you so much in advance.
Kind regards.
PS. This may help:
- The EpMon just seems a way to monitor the auxiliar PD output, but I still don't know what 'Mod In' is supposed to be.
- C11 and R18 are missing in the real circuit (open circuit I mean). I think the rest of the components are there.
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