Broadband color filters with arbitrary spectral transmittance using a liquid crystal tunable filter (LCTF)
Kanae Miyazawa, Kazuhiko Kurashiki, Markku Hauta‐Kasari, Satoru Toyooka · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2002
We propose an experimental setup for an imaging system using a liquid crystal tunable filter (LCTF) to implement rewritable transparent broad-band color filters with arbitrary spectral transmittances. Holding-time for each transmitting wavelength of the LCTF is controlled corresponding to a computationally designed filter function, and a time-integrated intensity image is taken with a monochrome CCD camera through the LCTF. The averaged norm error between the implemented and the expected filter functions was about 10%. The system can be applied to spectral estimation, spectral based classification and spectral based parametr estimation.