Fabrication of micropolarizer and narrow band-pass pixel filters for focal plane array
Date of Award
M.S. in Electrical Engineering
Advisor: Andrew M. Sarangan
Pixel level optical filters such as micropolarizer arrays for polarimetric imaging and dielectric interference filters are rapidly becoming viable technologies for image enhancement for visible to near-IR wavelengths. The research in fabricating arrays of micropolarizer filters that has been done in the last decade focused on multiple different fabrication methods with various results in performance with respect to extinction ratio and TM transmission that generally follow the trend that they improve as the fabrication method and materials becomes increasingly complex. While the design and fabrication of multilayer metal-dielectric interference filters is more established, there are many unidentified pixel level implementations that offer several possibilities of multiple filter designs and types on the same imager array. This work serves to address some of these complex fabrication issues and offers a rudimentary technique for fabricating micropolarizer arrays based on combination interference and contact lithography method with Damascene metallization of aluminum wire-grids with good possible performance in extinction ratio and TM transmission. This thesis also details a multilayer narrow band-pass filter design and offers discussion on practical implementation with an imaging system. Pixel level grating structures of three orientations are fabricated, polarizers are developed on glass for testing, multilayer filter designs are generated, and the feasibility of directly bonding these filters onto a CCD imager array is experimentally determined. The body of this work addresses the problems encountered with this novel wire-grid fabrication process and with multilayer filter design and calibration steps while presenting the solutions implemented to realize these filters on the pixel level.
Polarizers (Light) Design and construction, Light filters Design and construction, Infrared imaging
Copyright 2011, author
Watson, Alex, "Fabrication of micropolarizer and narrow band-pass pixel filters for focal plane array" (2011). Graduate Theses and Dissertations. 391.