Beam combining

[werner1619]

anyone remember the post about combining rgb beams that had to do with getting all 3 beams in the right phase when combining?
I can't seem to find it???

thx
w.

[allthatwhichis]

I am not sure what you mean by "phase". You need to get them all on one level "plane" to get good near field alignment...

[werner1619]

sorry, polarization would be the correct term to use

[allthatwhichis]

You only need different polarization when you are combining two beams of the same color using a polarized beam splitting cube as your optic.

Regular... RGB combining only needs a dichro for each combination, R/G, Y/B... You do not need to worry about polarization of your beams to make white from RGB.

[buffo]

Technically there is one other time where polarization is relevant: if you want to use a PCAOM to modulate the color. There was a discussion a while back about using a PCAOM for color modulation to overcome the jellybeaning problem of most DPSS lasers. Sure, you loose 15-20% of your power, but you can modulate at insanely high speeds. The caveat is that all beams entering the PCAOM crystal have to have the same polarization.

However, this was an exceptional case. Most people simply modulate the laser driver, and live with the jellybeaning problem. And if you do that, then the polarization angle is irrelevent.

Adam

[werner1619]

thanks for putting me back on line guys!
w