A discussion was going on on LP about combining beams. It was the usual let’s serial several pbs cubes to make ridiculous energies. However it got me to think and here is what I thought.
we use one cube to combine two beams. There is no reason you could not send multiple beams through the cube and stack them like a knife edge. So say put 4 S polarized and 4 Polarized beams into one cube. This eliminates the mirrors needed for the knife edges and with a quarter wave plate leaves you with a stack half as wide.
ok great no great revolution. Now use a broadband cube and withe a single 1 inch cube you could combine all the rgb lasers into a very compact set of 3 coplanar beams. Those go to the usual dichro for combining.
a good application would be quad red, dual green, dual blue with mixed wavelength of each to enrich the color space all in one cube. Think 3d use of the cube surfaces. Reds at top green in middle blue on the floor or turn it sideways.
it would also shrink the rgb source a lot and best of all intrinsically fix a lot of the geometry so things won’t drift. In fact even heat is canceled since all beam will drift the same amount. I don’t think index of refraction would change enough to matter. If it did back to three cubes with a single red quad cube.
ok that’s the idea. Have fun and if you build it let me know.