Crystal oscillators are loosely divided from the frequency they operate at and whether they are elementary oscillators—work for the frequency marked within the can or at even multiples of that (overtone oscillators). Substantial-repetition-rate and large-ability picosecond regenerative amplifier according to one bulk Nd:GdVO4 crystal 的很多特性，如温度稳定性，老化稳定性，等效电路参数... https://www.hxcrystals.com/seokeywords/bulk-crystal-oscillator.html