MEMS Optical Cavity with Anomalous Dispersion (MOCAD)

Sensitivity enhancement of optical inertial sensors has shown to be possible by using anomalous dispersion media. Although the scale factor and signal to noise ratio can be greatly improved by exploiting anomalous dispersion the signal extinction is a major issue. Our previous effort demonstrated critical components to achieve millimeter scale optical cavities with anomalous dispersive gas media, and these efforts confirmed that shorter path lengths enabled enhancement with greatly reduced absorption. Our previous efforts also demonstrated critical components and processes to align and assemble microscale optical components to exploit the anomalous dispersion effect.   This Phase II proposal will develop compact and robust implementation of a micro optical cavity an anomalous dispersive gas media and develop a mm-scale inertial sensor to utilize this technology. The goal is not only to demonstrate the benefits of anomalous dispersion for inertial sensors, but also create a robust, passively-aligned microfabricated cavity, eliminating much of the complexity inhibiting production and manufacturability. Several technologies are leveraged to accomplish this including spherical and 45° micromirrors, kinematic constraints using V-groves, and precise bonding at the die level. The dispersive media cell design will leverage dispensers that eliminate the need for highly specialized high-vacuum equipment and ensure the quality of the media cell. The integration of a microoptical cavity with dispersive media will enable shorter path lengths and less attenuation in the optical path.