Wavelength tunable optical filter and method for switching and adjusting thereof
US11287714B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Apr 3, 2017 |
| Grant date | Mar 29, 2022 |
| Priority date | — |
| Expiry date | Apr 6, 2037 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F2203/055
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A wavelength tunable optical filter and a method for switching and adjusting the wavelength tunable optical filter. The optical filter includes a liquid crystal cell comprising a cholesteric liquid crystal mixture inserted between two electrodes configured to apply a voltage, the cholesteric liquid crystal mixture comprising a chiral dopant and a dual frequency liquid crystal host material, the liquid crystal cell having a reference Bragg reflection wavelength in the spectral range between 300 nm and 900 nm, and the liquid crystal cell having a first Bragg reflection wavelength, when the applied voltage is modulated at a frequency comprised in an intermediate frequency range which is above a cross-over frequency and below a high frequency limit, the first Bragg reflection wavelength being different from the reference Bragg reflection wavelength and the cholesteric liquid crystal mixture being non-scattering both in the reference Bragg reflection mode and in the first Bragg reflection mode.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.