Fast Agile Tunable Filter for Spectral Imaging System

The Department of Energy is seeking to develop electronically tunable optical spectral filters for hyperspectral imaging (HSI) systems, in order to detect the proliferation of nuclear, chemical, and biological weapons, assess bomb damage, and evaluate terrorist incidents and disasters. To identify a wide range of materials, these filters must cover a wide spectral range, from visible to IR (i.e., from ~350 nm to 2000 nm), with fast tuning (within several milliseconds) and high optical throughput (>40%), without mechanically moving parts. However, existing filters are limited in their tunable spectral range, tuning speed, and are bulky with respect to mechanical movement. This project will develop a new electro-optic, fast agile tunable filter (FATF). The filter will be based on thin film filters constructed from several tunable Fabry-Perot etalons, with wide spectral range tuning provided by the fast mode of liquid crystal electro-optical effect. FATF will be a monolithic, thin (<10 mm), compact, low-voltage-power (<10 V, <0.1 W) device that meets the DOE requirements in spectral range, tuning speed, and optical throughput. In Phase I, a proof-of-concept demonstration device will be designed and built to validate the key filter performance parameters required for the DOE application. Commercial Applications and other Benefits as described by the awardee: When used in remote-sensing equipment, such as the airborne spectral imaging equipment, the FATF should enable the identification of activities associated with the proliferation of weapons of mass destruction. Commercial applications should include biomedical imaging, commercial remote sensing, environmental monitoring, and homeland security.