Dual beam single-mode vertical cavity surface emitting lasers using high-index contrast grating

We demonstrate the dual beam emission from single-mode vertical cavity surface emitting lasers (VCSELs) with high-index contrast sub-wavelength grating (HCG) as a top mirror. The modeling and experiment on amorphous-Si/SiO2 HCG clearly shows the large angular dependence of reflectivity, which enables the dual beam emission with a large tilt angle. We fabricated VCSELs with the angular dependent HCG. We observed dual beams with 45° tilted directions which are engineered by the angular dependence of HCG.