Abstract:A high-refractive-index contrast subwavelength grating （HCG） for 940 nm GaAs-based VCSEL is reported. The reflector is composed of GaAs and AlOx. The effects of the grating parameters of TE-HCG on refractivity are discussed in detail. And the structural characteristics of TE-HCG and TM-HCG are analyzed， especially the influence of their topography errors on the high reflection band. The 940 nm TE-HCG has a large reflection bandwidth of up to 97 nm with its reflectivity for TE incident light more than 99.5%， and the ratio of Ratio of high reflection band to central wavelength is more than 10%. But for TM incident light its reflectivity is less than 90%. It is worth mentioning that the VCSEL with such a TE-HCG can be prepared by one-time epitaxial growth technology， which helps to improve the performance of the device. Furthermore， it greatly reduces the manufacturing difficulty and cost of a VCSEL.