Femtosecond (fs)-laser micromachining is an effective material processing method because of its ultrashort pulse width and extremely high peak intensity. Fs-laser micromachining technology has been widely used to process photonic integrated devices. Lithium niobate (LN) crystal is a common material in integrated and guided-wave optics because of its excellent electro-optic, nonlinear optical, and piezoelectric properties. This review describes fs-laser processing of LN crystal, mainly focusing on the physical principle of fs-laser processing and the recent advances of LN-based photonic devices. Fs-laser technology makes LN crystal a promising platform in the field of micro-nano photonics.
