Fast wavelength switching in semiconductor micro-ring lasers using filtered optical feedback

We investigate the wavelength switching speed in semiconductor lasers that are wavelength tunable based on filtered optical feedback. The feedback section consists of two arrayed-waveguide gratings and four semiconductor optical amplifiers. The wavelength tuning and switching is controlled by changing the currents injected in the semiconductor optical amplifiers. We achieve a few nanoseconds wavelength switching speed. We also investigate how this switching speed depends on the phase and the amplitude of the feedback. We compare the experimental observations with numerical simulations based on a rate-equations model, from which we can identify the most important parameters that influence the switching speed.