Wavelength Switchable Semiconductor Laser Based on Half-Wave Coupled Fabry–Pérot and Rectangular Ring Resonators

A wavelength switchable semiconductor laser based on half-wave coupled Fabry-Pérot and rectangular ring resonators is proposed and demonstrated. The device consists of all-active waveguides to facilitate the fabrication. The cavity lengths are designed with a small difference to employ the Vernier effect to obtain large wavelength tuning. A half-wave coupler is used to produce a phase-dependent loss, thus achieving a high side-mode suppression ratio (SMSR). By adjusting the current applied to just one electrode, six-channels wavelength switching with 200-GHz spacing is measured by the carrier injection effect, with a current variation of only about 20 mA. At higher current injection level, the thermal-optic effect becomes dominant, which produced eight-channels wavelength switching in the opposite direction with a maximal SMSR of 38.5 dB.