Full-color reflectance-tunable filter based on liquid crystal cladded guided-mode resonant grating.
This work proposes a tunable reflective guided-mode resonant (GMR) filter that incorporates a 90° twisted nematic liquid crystal (TNLC). The GMR grating acts as an optical resonator that reflects strongly at the resonance wavelength and as an alignment layer for LC. The 90° TNLC functions as an achromic polarization rotator that alters the polarization of incident light. The resonance wavelength and reflectance of such a filter can be controlled by setting the angle of incidence and driving the 90° TNLC, respectively. The designed filter exhibits a very large spectral shift in resonance wavelength from 710 to 430 nm, which covers the entire visible spectrum. The transmittance can be tuned to within 10 V at various resonance wavelengths. The hybrid GMR - LC filter is compact, has a simple design, and is easy to fabricated. It can therefore be used in practical applications.
Chun-Ta
CT
Wang
Hao-Hsiang
HH
Hou
Ping-Chien
PC
Chang
Cheng-Chang
CC
Li
Hung-Chang
HC
Jau
Yung-Jr
YJ
Hung
Tsung-Hsien
TH
Lin