Crystal oscillators are loosely divided by the frequency they work at and whether or not they are essential oscillators—get the job done for the frequency marked to the can or at even multiples of that (overtone oscillators). We existing a Nd:GdVO4 bulk crystal oscillator with >70 WTEM00 laser output based https://sound-social.com/story8968301/not-known-details-about-bulk-crystal-oscillator