Strain-enhanced polarization sensitivity in β-Ga2O3 photodetector

Polarization-sensitive photodetection and imaging have great application value in fields such as polarization division multiplexing optical communication, remote sensing, near-field imaging and military monitoring. Pursuing a high polarization ratio has always been the research hotspot in polarization-sensitive photodetectors. In this paper, we report a compression strain enhanced polarization ratio in β-gallium oxide (β-Ga2O3) single crystal flake. A rigorous crystallographic analysis confirmed its high crystalline quality and orientation. Angle-resolved polarization Raman spectroscopy (ARPRS) was adopted to study the anisotropy of its optical properties. Extensive ARPRS measurements and theoretical calculation consistently demonstrate the strong optical anisotropy in the high-quality β-Ga2O3 flake. A polarization ratio of 0.96 was obtained in the flat β-Ga2O3 flake. Furthermore, mechanical strain of ±0.7