Tunable dual-wavelength laser constructed by silicon micromachining

This paper presents a tunable dual-wavelength laser by integration of a semiconductor gain chip with silicon-micromachined grating and mirrors onto a silicon substrate. The wavelength tuning is demonstrated by rotating the micromirror. With one wavelength being tuned and the other fixed, the laser output presents a tunable spectral separation from −28.38to+24.18nm. The laser output reaches 2.9mW with far-field divergences of 37° and 30° in the vertical and horizontal directions, respectively. Besides, line broadening is observed with the reduction of the spectral separation.