Crystal oscillators are loosely divided via the frequency they perform at and whether or not they are essential oscillators—operate within the frequency marked about the can or at even multiples of that (overtone oscillators). High-repetition-price and higher-ability picosecond regenerative amplifier dependant on an individual bulk Nd:GdVO4 crystal 的很多特性，如温度稳定性，老化稳定性... https://bookmarksoflife.com/story4540664/the-single-best-strategy-to-use-for-bulk-crystal-oscillator