Tunable External Cavity Diode Laser with a PLZT Electro-Optic Ceramic Deflector

A stable tunable diode laser which uses an electrooptic deflector incorporated into a Littrow-type external cavity as a wavelength tunable element is proposed and demonstrated. The deflector is fabricated by lead lanthanum zirconate titanate (PLZT) electrooptic ceramic with high quadratic electrooptic effect. Two half-wave plates and a large angle triangular electrode of PLZT electrooptic ceramic are designed to acquire a high frequency-voltage tuning ratio. By adjusting the voltage applied to the deflector, a large single-mode tuning range of 420 GHz (including mode hops) and a frequency-voltage tuning ratio of 840 GHz/kV have been achieved at 780.5 nm.