stabilized 532nm laser
Michael Koch
I need a green 532nm laser with stabilized output power. The output
power should be constant within +-1% over 10 minutes. If I drive the
1064nm diode with constant output power (using the internal monitor
diode), is then the 532nm output also stabilized? Or does the efficiency
of the frequency doubler depend on temperature?
Thanks,
Michael
Samuel M. Goldwasser
It must be actively output power regulated. Just controlling the diode
won't provide stability except perhaps after a long warmup but then there
will still be some drift. EVERYTHING affects the output power.
The JDSU uGreen and Coherent C215M and C315M would probably meet this
over 10 minutes even though long term stability specs might be worse.
The older uGreens using the HyB B controller may actually be better as
they use an actual analog control loop for the power regulation.
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Michael Koch
> It must be actively output power regulated. Just controlling the diode
> won't provide stability except perhaps after a long warmup but then there
> will still be some drift. EVERYTHING affects the output power.
Understood. That means I need a beamsplitter in the output beam, and
measure the power there. May I assume that the polarization angle of the
laser is constant? If not, the power measurement would be difficult
because the beam splitter may be partly polarizing.
Michael
Samuel M. Goldwasser
If you're going to build your own, that's what needs to be done. The
polarization of the output of Nd:YVO4-based green lasers is pretty good
since vanadate has a strong polarization preference. But an Nd:YAG laser
may not.
But, it would be a lot easier to buy one. For 10 mW, there are inexpensive
options as I think I noted in the original posting-reply.
You can pick up a surplus/used C215M or uGreen system for well under $1,000US.
Michael Koch
> But, it would be a lot easier to buy one. For 10 mW, there are inexpensive
> options as I think I noted in the original posting-reply.
As I have already a cheap 532nm laser and a LDC-3724A laser driver, it
seems not too difficult to try it with a beamsplitter and a photodiode.
I think an additional IR-blocking filter in front of the photodiode is
useful, as I don't want to detect the 1064nm radiation.
Thanks for your answers,
Michael
Samuel M. Goldwasser
Yes, you'll need the filter unless your laser already has one. The LCD-3724A
should be able to control it assuming you can drive the pump diode directly.
If not, there may be issues of the existing driver limiting bandwidth....
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Michael Koch
> Yes, you'll need the filter unless your laser already has one.
Of course the laser has already a filter, but I don't know how good it is.
> The LCD-3724A should be able to control it assuming you can drive
> the pump diode directly.
Yes, I will remove the original driver from the laser.
Michael
Samuel M. Goldwasser
Make sure the ILX box can't overdrive the diode!!!! I don't know how
effective its current limit is during modulation.