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:
May. 16, 1989
Filed:
Oct. 09, 1986
Fuji Photo Film Co., Ltd., Kanagawa, JP;
Abstract
A light modulator comprises a stack of a wave guide layer and an adjacent layer normally exhibiting a refractive index smaller than that of the wave guide layer, at least one of these layers being formed of a material whose refractive index changes by application of energy. An energy applicator is provided at least in one of these layers, and a dielectric grating is positioned at the surface of the adjacent layer over a section where energy is applied by the energy applicator. A drive circuit is provided for energizing the energy applicator and causing a change in refractive index to arise in the wave guide layer and/or the adjacent layer so that a wave guided inside of the wave guide layer is radiated out of the stack by interaction with the dielectric grating. In a wave guide device, the wave guide layer is formed of a thermo-optic material in which the thermal coefficient of refractive index is zero or negative, and the adjacent layer is formed of a thermo-optic material exhibiting a positive thermal coefficient of refractive index.