High-contrast grating optimization for electrically pumped 1060nm MEMS-VCSELs

In our paper, the design of a high contrast grating is optimized to obtain a wider reflectivity bandwidth. HCGs present an incidence angle dependence that can affect the reflectivity bandwidth. This dependence was mitigated by reducing the duty cycle of the HCG. A further optimized model was done by matching the reflectivity phase with the phase of the incident Gaussian wavefront. The broader bandwidth of the new designs was calculated using simulations. Subsequently the MEMS VCSELs with the new designs of HCG were fabricated. The highest tuning range obtained for the focusing design was 45nm and for the low duty cycle design 38nm. These ranges are lower than the standard design due to differences from the design. Further improvements in the fabrication process are required to demonstrate the new designs proposed.