Crystal oscillators are loosely divided through the frequency they operate at and whether or not they are fundamental oscillators—perform at the frequency marked around the can or at even multiples of that (overtone oscillators). Substantial-repetition-level and high-electrical power picosecond regenerative amplifier based upon only one bulk Nd:GdVO4 crystal HTML White https://socialwebconsult.com/story4356794/bulk-crystal-oscillator-for-dummies