Open AccessTunable electrochromic filter for in situ Fourier spatial frequency filtering
Author(s) -
Alexander Hein,
Bastian Kaiser,
Carsten Kortz,
E. Oesterschulze
Publication year - 2021
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.418048
Subject(s) - electrochromism , spatial filter , optics , spatial frequency , fourier transform , fourier optics , materials science , filter (signal processing) , optical filter , computer science , realization (probability) , electrochromic devices , transmission (telecommunications) , optoelectronics , physics , telecommunications , computer vision , electrode , statistics , mathematics , quantum mechanics
Spatial optical Fourier filtering is a widespread technique for in situ image or light field processing. However, conventional fixed absorbing patterns or mechanical irises only allow an inflexible, very restricted control. Thus, we present two electrochromic spatial filters with ring-shaped or directional segments, which can be individually addressed and continuously tuned in transmission resulting in up to 512 different filtering states. For realization of the electrochromic devices, we overcome technical obstacles to realize seamless, gap-free electrochromic segments. We describe this novel fabrication process and demonstrate the successful application in an optical Fourier transform set-up.