Influence of grating parameters on reflectivity of Si/SiO₂ high contrast gratings

In order to solve the problem of poor stability of high contrast gratings (HCGs) for 850 nm VCSEL, a new type of Si/SiO₂ HCGs was put forward. The influence of grating parameters on HCG reflectivity of 850 nm was studied. The influence of the grating parameters, such as height, fill factor, duty, etching depth, angle, on the reflectivity of Si/SiO₂ HCGs for 850 nm was simulated and analyzed by the finite element analysis software. For the 850 nm TE light incidence from SiO₂ to the rectangular HCGs, it is found that only when the angle of gating is greater than 88°, can the reflectivity of HCGs be greater than 0.995, and other parameters of HCGs have a larger tolerance.