Tunable External Cavity Laser Based on Liquid Crystal Fabry-Perot Interferometer and Liquid Crystal Phase Shifter

An innovative non-mechanical and low power consumption continuous wavelength tunable external cavity laser (ECL) using liquid crystal tuning elements is demonstrated. The laser system consists of a gain chip, a collimating lens, tuning elements, and a partial reflection mirror. The tuning elements include a liquid crystal Fabry-Perot interferometer (LC-FPI) and a LC phase shifter. The LC-FPI fulfills the mode-hopping tuning and the continuous tuning is achieved by the LC phase shifter. A coarse wavelength tuning range of 40 nm and sidemode suppression of about 25 dB is obtained.