Crystal oscillators are loosely divided from the frequency they get the job done at and whether or not they are elementary oscillators—perform on the frequency marked within the can or at even multiples of that (overtone oscillators). High-repetition-amount and substantial-energy picosecond regenerative amplifier based on one bulk Nd:GdVO4 crystal 的很多特性，如温度稳定性，老化稳定性... https://bookmarkbells.com/story19003691/the-basic-principles-of-bulk-crystal-oscillator