NEOS PCAOM output Problem

[dream beamz]

I have recently acquired a PCAOM and Driver and am running into a problem with it. I am using a coherent I-90 argon-krypton gas mix whitelight laser with a 10 watt crystal and a 4 channel driver. I have mounted several pcaoms in smaller systems but never one of this caliber. Here is my issue, when I run the laser through the crystal the best output I can get on the first order beam is 40% of the original, zero order has most of the other 60%. I know my laser has vertical polarization so I have mounted the crystal appropriately. Here is my guess; I have recently bought two PCAOM sets. One, an 8 channel driver with the 10w crystal and a 1w with a 4 channel driver. I am now using the 4 channel driver with the 10w crystal. Are the drivers set for the crystal and if so, how can I get the 4 channel driver made to work to the full power of the crystal. If you need more information to my setup, please e-mail me but I will put a list below

Thank you in advance,


coherant I-90 argon-krypton gas mix whitelight laser producing 3 watts
Neos driver Model number N64040-75-.1-4CH-5-M
Neos 10w Crystal
Full-auto pro software

Driver wiring:
Full auto DB25 Pin 9 to Neos DB9 Pin 1
Full auto DB25 Pin 10 to Neos DB9 Pin 2
Full auto DB25 Pin 20 to Neos DB9 Pin 3
Full auto DB25 Pin 10 to Neos DB9 Pin 4
Full auto DB25 Pin 7 to Neos DB9 Pin 5
Full auto DB25 Pin 10 to Neos DB9 Pin 6
Full auto DB25 Pin 19 to Neos DB9 Pin 7
Full auto DB25 Pin 10 to Neos DB9 Pin 8
Full auto DB25 Pin 18 to Neos DB9 Pin 9

Full auto 7 = Blue lo
Full auto 9 = ground
Full auto 10 = +vdc
Full auto 18 = red hi
Full auto 19 = green hi
Full auto 20 = blue hi

[aijii]

Have you tried using the 8 channel driver with the 10 watt crystal just to see how it works ?

[aijii]

Have you tried using the 8 channel driver with the 10 watt crystal just to see how it works ?

[dream beamz]

yes with same results and the 8ch was wired by bob ashe of new method lasers so i am sure the wireing is correct

[LaserLover]

Have you tried rotating the PCAOM crystal on it's axis slightly in either direction from normal?

Rick

[dream beamz]

yes although i cant tell if the results are good, my notion is that the tube could be mounted slightly offset and hence cause the polorazation to be a little off from verticle. I just dont have a mount that swivles for accurate trials of this method. Can you point me in a good direction

[LaserLover]

You could try tilting your laser either way to test that theory before going to the expense of buying a rotary type of mount from Melles Griot or Thor Labs.

Rick

[dream beamz]

I wished This laser doesnt exactly tilt with ease

You could try tilting your laser either way to test that theory before going to the expense of buying a rotary type of mount from Melles Griot or Thor Labs.

Rick

[LaserLover]

Ok,
The next best thing is find a broadband 1/2 wave plate that you can rotate within the beam to change polarization and see what happens.
It also might be possible that your laser controller card is not outputting a high enough signal to drive the NEOS RF driver at peak levels.
You might want to scope out the signal to see what's happening.
You could use a signal generator with TTL output to trigger the RF NEOS driver to make sure it's getting the proper signal.
Also rexamine your beam path setup as sometimes mirrors can change beam polarization between the laser and the PCAOM.
Good Luck
Rick

[dream beamz]

Two good ideas I havent thought of. The broadband plate and signal levels from full auto. I will check signal levels first as i think this may be the culpret. There is no beam path issue, seeing that this is an ArKr gas mix laser I did not need combining optics on this laser. Beam goes from laser past shutter into pcaom, man if it only worked so easy as i initially thought it would.............

Ok,
The next best thing is find a broadband 1/2 wave plate that you can rotate within the beam to change polarization and see what happens.
It also might be possible that your laser controller card is not outputting a high enough signal to drive the NEOS RF driver at peak levels.
You might want to scope out the signal to see what's happening.
You could use a signal generator with TTL output to trigger the RF NEOS driver to make sure it's getting the proper signal.
Also rexamine your beam path setup as sometimes mirrors can change beam polarization between the laser and the PCAOM.
Good Luck
Rick