SINGLE LITHIUM-NIOBATE CRYSTAL FOR MODE SELECTION AND PHASE MODULATION IN A TUNABLE EXTENDED-CAVITY LASER-DIODE

A 1540-nm external-cavity laser diode with an intracavity electro-opti c wavelength tuner is demonstrated. Coarse- and fine-wavelength tuning is achieved with a single lithium niobate wavelength tuner. One secti on of the crystal is used as a tunable-wavelength filter to tune the w avelength by mode hopping. The other operates as a phase modulator to change the optical length of the cavity and to tune the wavelength con tinuously. Coarse tuning by mode hopping is obtained over a range of 5 .3 nm with a tuning rate of 580 MHz/V. Continuous tuning is obtained o ver 82% of the free spectral range of the cavity. The wavelength switc hing time is 10 ns for the cavity used.