Integrated tunable semiconductor ring laser with fast wavelength switching using filtered optical feedback

We report on an integrated approach to achieve fast wavelength switching in a semiconductor ring lasers using on-chip filtered optical feedback. The feedback section consists of two arrayed waveguide gratings and four semiconductor optical amplifiers. The wavelength tuning and switching are controlled by changing the injected currents into the semiconductor optical amplifiers. Experimental observations and numerical simulations show a wavelength switching speed of few nano seconds. We also investigate the effect of the feedback parameters and the noise strength on the wavelength switching speed.