Open AccessNarrowband multispectral filter set for visible band
Author(s) -
K. Walls,
Q. Chen,
James P. Grant,
Steve Collins,
David R. S. Cumming,
Timothy D. Drysdale
Publication year - 2012
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.20.021917
Subject(s) - optics , materials science , narrowband , multispectral image , electron beam lithography , optical filter , optoelectronics , filter (signal processing) , lithography , fabry–pérot interferometer , wavelength , layer (electronics) , resist , physics , nanotechnology , computer science , computer vision
We design, fabricate and characterise a narrowband Fabry-Pérot multispectral filter set for the visible range (400-750 nm) that is suitable for integration onto complementary-metal oxide-semiconductor image sensors. We reduce the fabrication steps by fixing the physical cavity length and altering the effective optical length instead. Using electron-beam lithography, a sub-wavelength hole array is patterned in a silicon nitride cavity layer, backfilled with poly(methyl methacrylate), and bounded by aluminium mirrors to create 23 filters with full-width half-maximums of 22-46 nm. Additionally, for colourmetric reproduction applications, using as few as 10 filters gives a colour difference (CIEDE2000) of 0.072, better than trichromatic filters.