The two oscillator circuits down below are well suited for applying crystal oscillators in sequence or parallel mode: High-repetition-charge and superior-energy picosecond regenerative amplifier determined by a single 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 substantial ability passively manner-locked picosecond oscillator ... https://www.hxcrystals.com/seokeywords/bulk-crystal-oscillator.html