- Dec 13, 2007
It looks like the crystals might be out of alignment. Did you drop it or something? And does it seem to have less power overall?
The crystals cant get out of alignment, they are glued together. The combined set are also glued in place, the exit point from the set is what changes. Once that happens the beam will enter the expander at a different angle, the result is glare off the edges of the expander and a crooked beam which is collimated by the final output lens. If the shape of the beam exiting the expander is altered, even by a fraction, it becomes very noticable on the wall.
This behaviour is also seen when you burn up a set (t00 much pump), any damage from heat becomes permanent and etched into the nd:YV04 as a dark spot.