Polys are 4 or more sided FSMs mounted on a pcb with motor for scanning or making liquid sky etc. sometimes you can find just the mirror part- they are in the bottom of older all-in-one printer /scanners Fred at surplusshed.com has a nice big one(24vdc). most of the FSMs I have are kinda thick and my not be the best for your applications. I will be making them available via DAoOs new site(open soon)darklasers.com Also I can cut them to length or DAoO will have squares with blackened edges in stock very soon. Heres the (approx)WTL(width,thickness, max. Length)of present stock: widest I have is 15/16-at 1/4 thick and up to 12 inches long-----followed by11/16 by 1/8th by 8inches---9/16 by 3/16th at 8 inches max---1/4" wide by 1/8th up to 8 inches long and 7/32 by 1/8th also 8 inch max. length. I cannot tell you if these are 'tuned' for any certain wavelength but they work great for all my ss and gas lasers so far.(red,green,BR,R&G henes and argon single and multiline)please PM for more info--thanks--<(*v*)>hak