1. No visible purple tint that changes color with angle and ambient lighting in the crystal, probably undoped YV04 used as a high index of refraction optic.
2. C Band coating, 1550 nm. Doped Vandate does not lase significantly in 1550 region.
Rough conclusion: Its a compensator optic of some sort for a Mid IR telecom device and not a laser crystal.
For known good laser crystals, I'm going to put a plug in here for my former employer, Altos Photonics. You might pay 2X over Ebay, but Russian grown crystals and Lithuanian Optical Coatings are actually quite good. (Well, Actually superb !) That way you know what your getting and the prices are reasonable. If you dig deep enough into the Altos Website you'll find the Eksma Optics laser crystals page (Not the Rods page) with actual US prices. If not, call the office and get a quote.
Really, really, screaming lasers need "capped" vanadate with un-doped ends fused onto the doped Vanadate or you need a high Quality oriented and coated crystal like Altos sells.
Having built or repaired a few lasers, I'm weary of Ebay DPSS parts. Eksma treats their parts as if they are all destined for lab service, so the coatings are good and the orientations are correct.
Steve
Last edited by mixedgas; 10-31-2014 at 10:55.
Qui habet Christos, habet Vitam!
I should have rented the space under my name for advertising.
When I still could have...