The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 14, 1994
Filed:
Feb. 03, 1992
Nippon Telegraph and Telephone Corporation, Tokyo, JP;
Abstract
A tunable wavelength-selective filter includes a glass substrate, a transparent electrode layer, a highly reflective mirror, an alignment layer, a liquid crystal layer, another alignment layer, a transparent material layer whose refractivity index is substantially equal to that of the liquid crystal layer, another highly reflective mirror, another transparent electrode layer, and another glass substrate, which are stacked in this order. An etalon cavity of the filter includes two layers, the liquid crystal layer and the transparent material layer (such as a glass plate), which enables the cavity length to be increased without increasing absorption and scattering of the cavity. This makes it possible to narrow the FWHM, quicken the response time, and increase the transmittance of the filter. Applications for the filter include a double cavity structure tunable wavelength-selective filter of a wide tunable range, and a photodetector of a simple construction.