Patent — available for licensing
All-Solid-State Frequency Agile Filter (AF2)
A NASA invention available to explore as a licensing opportunity.
About this technology
Overview
A thin-film interference filter (TFIF) is an optical device that uses light interference to selectively transmit, reflect, or block specific wavelengths. TFIFs are used in imaging systems like LiDAR to control the light reaching the detector and are easily mass-produced with excellent optical performance. However, TFIFs typically target specific wavelengths or narrow bands. Thus, multispectral applications require multiple TFIFs. Traditionally, this is done with motorized filter wheels, which add bulk, cause slower response, limit spectral resolution, and introduce moving parts subject to wear and tear. Alternatively, liquid crystal tunable filters (LCTFs) enable rapid electronic tuning without mechanical movement, improving speed and compactness, though they still have limitations including polarization sensitivity, low throughput, narrow spectral range, slow switching times (milliseconds), and high cost. In an effort to improve upon the limitations of motorized filter wheels and available tunable filters, engineers at NASA’s Langley Research Center have developed an all-solid-state frequency agile filter (AF2) based on exotic phase change materials (PCMs). This innovative technology is capable of fast (MHz to GHz in nanoseconds) and wide (500nm – ~15 micrometer) spectral tuning. Furthermore, the filter has no moving parts and is polarization insensitive, making it an excellent solution for applications requiring multispectral filtering.