Mononolithically integrated external cavity wavelength tunable lasers with a diffraction grating and beam steering controller

We present an external cavity tunable laser based on beam steering and grating-assisted diffraction in a Littrow configuration by monolithically integrating a semiconductor optical amplifier, an etched grating, and a beam steering controller with two current injecting stripes. We have demonstrated the wavelength tuning by steering the beam toward the grating, which is controlled by varying the injection current into the stripe. As a result, the tuning range of 11.9 nm with the side mode suppression ratio from 35 to 45 dB has been achieved.