Looking for any info on AOMs

[ElektroFreak]

I've always been under the belief that directly modulating a DPSS or diode laser is bad for both lifetime and stability. Many times I've noticed that the output of certain DPSS lasers will fluctuate randomly when modulated, and sometimes mode-hopping will occur. I've decided that using an AOM (acousto-optic modulator) would be a way to ensure that my lasers maintain a stable output at TEM00 at all times while being modulated, even my cheaper ones.

I bought a used AOM from Meredith Instruments and so I'm interested in any helpful experiences LPF members may have had with them. A major question that I have is whether or not I can feed the TTL/analog signal directly into the AOM driver?

Any help with this matter would be greatly appreciated.

Thanks in advance
Pat

 

[GooeyGus]

yes I believe the mod signal goes directly to the driver, whether its a 0-5V type thing I have no idea.

Also, if that AOM is tuned for one wavelength (probably 633nm if it's the one I'm thinking of...) Then you wont be able to pass any 473 or 532 dpss. If it is muli-channel, then you may get one channel that is close enough, but it's a stretch.

Alignment is CRUCIAL with these. Spend the money on a good adjustable mount for it, or else your going to be seeing huge losses.

Expect huge losses anyway... 30% loss is not too uncommon...

Blanking a DPSS laser is not any worse for the laser than blanking a diode laser (because that is essentially what you're doing) but, like you said, DPSS has inherent stability issues when blanking.

AOM's are the way to go in a big system making big power. On a smaller system, the losses are large and it's more of a pain than it's worth, IMO.

That being said, I really hope you get it working. I've been eying those for a while.

 

[Cyparagon]

As gus said, laser diodes (and inherently DPSS) are made to be driven in pulses. The pulse rating is higher than the CW rating. That's all your DVD diode was ever going to do until you came along ;D

 

[ElektroFreak]

Thanks for the replies! Gus, you've definitely given me a lot to think about.. I'll just have to experiment and see how it goes..