A Wafer Level Packaged Fully Integrated Hyperspectral Fabry-Perot Filter with Extended Optical Range

We report on the first demonstration of a wafer level packaged, vacuum sealed, fully integrated and cell-phone compatible tunable micromachined Fabry-Perot filter $(\mu \mathrm{FPF})$ , operating within the visual and near-infrared (VIS-NIR) optical range. Implementation of a normally closed architecture combined with the electrostatic actuation enlarging, rather than closing, the optical cavity allowed unprecedented tunability of the optical gap between 600 nm and down to potentially 30 nm. The ability to support such a small gap size enables, for the first time, a transparent mode to such filters. Due to the 1 mm thickness of a vertically integrated Si-on-glass (SOG) fully assembled device, manufacturability and robustness of a single crystal Si mechanical structure, and its short response time, our hyperspectral filter can be directly integrated into mobile phone camera modules, hyperspectral imagers, and remote sensors.