Vertical cavity surface emitting laser and forming method thereof

The invention provides a vertical cavity surface emitting laser and a forming method thereof. The vertical cavity surface emitting laser comprises a substrate, a first mirror, an active layer, an oxide layer, a hole, a second mirror, a high-contrast grating and a passivation layer. The first mirror is located on the substrate. The active layer is located on the first mirror. And the oxide layer is positioned on the active layer. And the pores are positioned on the active layer and are surrounded by the oxide layer. And the second mirror is positioned on the hole and the oxide layer. The high-contrast grating is located on the second mirror, the high-contrast grating comprises a first grating part and a second grating part, and an air gap is formed between the first grating part and the second grating part; and a passivation layer over the high contrast grating, a first thickness of the passivation layer on the top surface of the first grating part being greater than a second thickness of the passivation layer