Crystal oscillators are loosely divided because of the frequency they work at and whether or not they are essential oscillators—function at the frequency marked around the can or at even multiples of that (overtone oscillators). We existing a Nd:GdVO4 bulk crystal oscillator with >70 WTEM00 laser output based upon the https://www.hxcrystals.com/seokeywords/bulk-crystal-oscillator.html