Crystal oscillators are loosely divided by the frequency they do the job at and whether or not they are essential oscillators—do the job at the frequency marked on the can or at even multiples of that (overtone oscillators). We current a Nd:GdVO4 bulk crystal oscillator with >70 WTEM00 laser output https://www.hxcrystals.com/seokeywords/bulk-crystal-oscillator.html