![Cat](images/smilies/pidgin/cat.png)
@ " Horizontal arrangement. I believe it's cylindrical lenses"
Attachment 50613....sounds unlikely (but possible) usually, a horizontal knife edge arrangement will use prisms and almost always, when PBS is being used (highly likely in this case), unless Phil has decided to sell polarised add on modules without mentioning it to his clients...(a big selling point would be missed here).
Reasoning:
If you knife edge horizontally, the beam is flat and wide which means unless you add an unnecessary reflection/mirror (not usually recommended unless strictly obligatory for space reasons) to the path of the reflected input into the PBS, the distance from collimator to cyl lens will be different for each side of said beam (cos its WIDE) and gets wider with every beam you add. This effectively eliminates any chance of getting a perfect focus in the farfield, and/or, will increase losses if you use a tight spatial filter.
![Frown](images/smilies/frown.png)
(always assuming here that you don't mix upwards into the PBS)
I think anyway that Phil would prefer you to ask him directly (that way he can say no if he wants to), rather than getting one of his clients (who is probably a friend) to open the lid on a new (virgin/squeaky clean/spotless) set of optics. What's more, I think he relies more on his skill and knowledge, rather than "secrets" to keep himself in business. I am fairly sure, that if you asked him, he would tell you.
Knowing how someone apparently did something, will not ensure that you can achieve the same results by copying them.
There is invariably a bit more to it than meets the eye....try painting a Rembrandt,Goya or a VanGogh or even get a machine to do it...it just aint the same!
However I have to admit, recognising where any possible errors are hiding, is always helpful when trying to design/build something.
Cheers
![Smile](images/smilies/smile.png)