A tilted wave (TW) laser based on the quasi-periodicity photonic crystal (QPC) structure is studied to improve the maximum power and wall-plug efficiency of laser diodes. In this work, we first use the longitudinal QPC structure instead of the thick passive waveguide compared with previously reported. In order to localize the first order mode, we designed and optimized the longitudinal QPC structure. The optical confinement factor (OCF) of the fundamental mode is only onesixth of the first order mode. In the experiment, a continuous wave power of 12.8 W at 980 nm is achieved with a peak power conversion efficiency of 57.2%. The laser emitted two nearly symmetric narrow vertical beams in far field pattern, which has a full width at half maximum (FWHM) of 7.6° each.
The semiconductor laser diode has the advantage of low cost, high efficiency, and compactness, but the beam divergence is too large to directly use. The phase-locked laser array is an efficient way to control the lateral lasing mode, which can help to achieve narrow farfield.. Though the lasing mode of phase-locked laser array can be an in-phase mode via Ywaveguide, integrated with phase shifter and external cavity, it still has a large side lobe in the farfiled. We demonstrated an on-chip phase and amplitude manipulation method to suppress the side-lobe in the farfield. The intensity of the sidelobes decrease from 0.307 to 0.109 and the integral energy of the main lobe increase from 52.5% to 60.5%