beam exspander with pbs cube

I want to buil a prodject using a pbs combining cube with 4 lasers on one side of the cube and four lasers on the otherside of the cube with a combined output of 8 lasers in 4 output beams...then pass those 4 beams through a strong convex lens to get a short focal point say 1 foot or less and then pass that focal point into a beam expander to get a variable small focal point that is adjustable for a small hot burning dot. WILL THIS WORK? Please respond if you know the answer...or have advice to get a 1-2 watt 405nm blue ray beam like this!

Won't work. PBS cubes will only combine two lasers, no more. You cannot use multiple PBS cubes either since they work based on the polarization of the incoming lasr light. There are only two possible polarizations, horizontal and vertical, so once you've combined both polarities you can't combine any more based on polarity.

The only other way to combine that many lasers of the same color into one beam is to use fiber coupling and collimate the fiber output.

EDIT.. I might have misunderstood your question.. If the PBS cube is big enough, you could combine 4 H polarized lasers on one side and 4 V polarized lasers on the other, yes. You can also take that output and combine them further using a conves lens but this will only give you a focal point, not a continuous beam. Alignment of the 8 lasers and the cube might be a little hairy, but I would think it is possible.

Heck I think you should try it and get back with pictures ! sounds to cool not to.

The very same question was asked by the same person here, and in various other places...