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:
Jul. 20, 1993
Filed:
Jul. 02, 1991
Yasuo Tomita, Yokohama, JP;
Hitoshi Oda, Sagamihara, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An optical modulation apparatus includes a semiconductor element having a quantum well structure, a unit for applying an electric field to the quantum well structure of the semiconductor element, a unit for supplying polarized probe light to the semiconductor element, the probe light emerging from the semiconductor element such that a polarization state thereof is changed by an electrooptical effect in the quantum well structure, a unit for causing the semiconductor element to receive pump light which causes virtual charge excitation in the quantum well structure, the virtual charge excitation screening the electric field applied to the quantum well structure, and a polarizer for converting a change in polarization state of the light emerging from the semiconductor element into a change in intensity.