Guest
Good day. I'm using a Michelson interferometer constructed on a cushioned optical table to measure deflections of small, pressurized membranes (2mm square and a few micrometers thick). We are currently using a small He-Ne for the light source, but would like to switch to a pulsed YAG (Continuum SureLite with the power significantly cut down) so that we can capture essentially instantaneous interferograms of the membrane being flexed dynamically (up to about 1kHz). Here's the problem: The (large and difficult to move) YAG is in one room, and my experiment is in the next room. So my professor says "no problem, rig up a series of mirrors to reflect the light from one room into the other and use it in your experiment". Riiigght, I say, but the laser light needs to be coherent for effective interferometry, and I question if the coherence will be maintained after reflection off 6 mirrors (each having lambda/10 flatness at best) and travelling a distance of about 60 feet. She says to try it anyway.<br><br>Who's crazy here? Do I have a prayer of generating clear interference patterns with this arrangement? Thanks!