In the past decades, there have been several attempts to create a tunable optical detector with operation in the infrared.
The drive for creating such a filter is its wide range of applications, from passive night vision to biological and chemical
sensors. Such a device would combine a tunable optical filter with a wide-range detector. In this work, we propose
using a Fabry-Perot interferometer centered in the mid-wave infrared (MWIR) spectrum with an HgCdTe detector.
Using a MEMS-based interferometer with an integrated Bragg stack will allow in-plane operation over a wide range.
Because such devices have a tendency to warp, creating less-than-perfect optical surfaces, the Fabry-Perot interferometer
is prototyped using the SOI-MUMPS process to ensure desirable operation. The mechanical design is aimed at optimal
optical flatness of the moving membranes and a low operating voltage. The prototype is tested for these requirements.
An HgCdTe detector provides greater performance than a pyroelectic detector used in some previous work, allowing for
lower noise, greater detection speed and higher sensitivity. Both a custom HgCdTe detector and commercially available
pyroelectric detector are tested with commercial optical filter. In previous work, monolithic integration of HgCdTe
detectors with optical filters proved to be problematic. Part of this work investigates the best approach to combining
these two components, either monolithically in HgCdTe or using a hybrid packaging approach where a silicon MEMS
Fabry-Perot filter is bonded at low temperature to a HgCdTe detector.