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:
Dec. 13, 1988
Filed:
Apr. 24, 1987
Norman Apsley, Malvern, GB;
Abstract
An electro-optical device is arranged as a Fabry Perot etalon comprising two mirrors and a central region. The mirrors are multilayer heterostructures of Al.sub.x Ga.sub.1-x As semiconductor materials where x alternates between 1.0 and 0.3. The central region may be a multiple quantum well structure of Al.sub.x Ga.sub.1-x As where x alternates between 0 and 0.3. The etalon material doping is non-uniform so that it is electrically a semiconductor device with a biasable central region. The optical path length in the central region is electric field dependent, and the etalon transmission or reflection is accordingly modulatable by varying the central region bias. The mirrors may be heavily doped and of opposite conductivity type with the central region undoped. This provides a PIN diode. Light incident on the etalon executes multiple transits of the central region. It is therefore unnecessary to employ long path lengths and high fields to enhance weak electro-optical effects in order to produce significant modulation, this being necessary in prior art devices.