The two oscillator circuits underneath are suitable for working with crystal oscillators in series or parallel manner: Large-repetition-level and higher-electric power picosecond regenerative amplifier based on an individual 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 higher electrical power passively method-locked picosecond ... https://www.hxcrystals.com/seokeywords/bulk-crystal-oscillator.html