Is this possible?

[Bionic-Badger]

The way a PBS cube works is that it only reflects light of a certain polarity. If your light is polarized perpendicular to that reflect-polarity it passes through the PBS without interaction.

In order to combine beams, one beam is in the pass-polarity, so it passes straight through. The other beam, polarized in the reflect-polarity direction, enters the cube from the side and reflects off the 45-degree polarity-reflective surface and out of the cube in the same direction as the pass-polarity beam, combining the two beams. Neither beam requires the other to interact/not interact with the cube.

 

[bobhaha]

Ok that makes sense. So the PBS is only set up to reflect one specific polarity in any direction. For some reason I was under the impression that the element inside the PBS had two coating, one will pass in one direction another will bounce in the other direction, meaning you could use interchange the PBS for any lasers polarization.

 

[flare09]

logically i dont see why this second picture was the first option. if you have the cubes pass all beams in say the vertical polarization and reflect in the horizontal, you essentially can just have a setup like a standard rgb dichro, pass beam one in vertical, reflect beam two in horizontal, while rotating it 90, and pass beams one and two vertical while cube two reflects beam three at horizontal polarization and turning it 90...ah hold on...but if you rotate it has to be only when beam two and three reflect. well scratch all that.

fuck it. put all three beams as close as possible and send it through 2 sets of focus, and expanding lenses, then focus it back down into one beam.
i do have to ask what is this actually for?