Polarization control and tuning efficiency of tunable vertical-cavity surface-emitting laser with internal-cavity sub-wavelength grating**Project supported by the Jilin Science and Technology Development Plan, China (Grant Nos. 20180519018JH and 20190302052GX), Jilin Education Department “135” Science and Technology, China (Grant No. JJKH20190543KJ), the National Natural Science Foundation of China (Grant No. 11474038), and the Key Project of Equipment Pre-Research Fund of China

Abstract

We design an 850 nm tunable vertical-cavity surface-emitting laser (VCSEL) structure using an internal-cavity sub-wavelength grating. The use of such a tuning structure allows for wider wavelength tuning range and more stable single-polarization as compared to conventional tunable VCSELs. The features of the internal-cavity grating effect on the wavelength tuning and polarization characteristics of the tunable VCSEL are analyzed. The simulation results show that the largest wavelength tuning range achieves 44.2 nm, and the maximum orthogonal polarization suppression ratio (OPSR) is 33.4 dB (TE-type) and 38.7 dB (TM-type).