A 795 nm gain coupled distributed feedback semiconductor laser based on tilted waveguides* *Project supported by the National Science and Technology Major Project of China (Grant Nos. 2017YFB0503100, 2018YFB0504600, 2018YFB2200300, and 2020YFB2205902), Frontier Science Key Program of the President of the Chinese Academy of Sciences (Grant No. QYZDY-SSW-JSC006), the National Natural Science Foundation of China (Grant Nos. 62090051, 62090052, 62090054,

Abstract

The 795 nm distributed feedback lasers have great application in pumping the Rb D1 transition. In this paper, in order to realize specific 795 nm lasing, we designed tilted ridge distributed feedback lasers based on purely gain coupled effect induced by periodic current injection windows through changing the angle of the tilted ridge. The fabricated devices were cleaved into 2 mm-cavity-length, including 5 tilted angles. The peak output powers of all devices were above 30 mW. Single longitudinal mode lasing was realized in all tilted Fabry–Perot cavities using periodic current injection windows, with side mode suppression ratio over 30 dB. The total wavelength range covered 8.656 nm at 20 °C. It was disclosed theoretically and experimentally that the output powers, threshold currents, and central wavelengths of the tilted ridge purely gain coupled DFB lasers were relevant to the tilted angles. The results will be instructive for future design of DFB laser arrays with different central wavelengths.