That's really cool, Chuck. I'm sure you know that lasers also can be used to create holograms, because they project pure light of only one wavelength. The web site you told us about has an ad for defraction gratings, for experiments with lasers. I'm wondering if the right combination of these gratings could in effect filter out all light that penetrates except for one wavelength. If so, could that produce some kind of hologram-like effect? Just thinking out loud -- Best wishes, Joe Chuck Hards <chuck.hards@gmail.com> wrote: And here's the place if 100mw isn't enough for you: http://www.dragonlasers.com/index.html?gclid=COD-8q-d3pMCFSEbagodYwcuZg _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://gallery.utahastronomy.com Visit the Wiki: http://www.utahastronomy.com