[Laser] Trihedral prism source?

[Tom Becker]

If this link doesn't work, search ebay.  I have several of these unusual 
reflectors, which have an NIR-filtered window at the vertex.  Great for 
returning both the originating beam and an NIR beam from the target, or 
detecting at the target  while returning the beam.  A sufficiently- 
narrow beam will, though, pass through the reflector if it is exactly 
centered.  I cannot locate the source I used, but I got them for less 
cost than the ebay supplier wants, as I recall.

http://cgi.ebay.com/CORNER-CUBE-PRISM-RETROREFLECTOR-with-IR-FILTER-laser_W0QQitemZ190286083429QQcmdZViewItemQQimsxZ20090211?IMSfp=TL090211143003r4037

Tom