The 2 oscillator circuits down below are suitable for making use of crystal oscillators in series or parallel method: Large-repetition-fee and high-power picosecond regenerative amplifier based upon just one bulk Nd:GdVO4 crystal 中原子或分子的排列具有三维空间的周期性，隔一定的距离重复出现，这种周期性规律是 A large electricity passively manner-locked picosecond oscillator dependant on... https://www.hxcrystals.com/seokeywords/bulk-crystal-oscillator.html