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:
Sep. 25, 2001
Filed:
Nov. 15, 1999
Shigeru Nakamura, Tokyo, JP;
Kazuhito Tajima, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
An optical switch is provided that utilizes a signal light frequency shift due to the resonance excitation non-linear optical effect in a semiconductor material so that a high extinction ratio optical switching operation can be realized with low energy controlling light pulses. The non-linear optical waveguide,receives a signal light pulse of a frequency of &ohgr;,and a controlling light pulse of a frequency of &ohgr;,and sets the pulse width of the controlling light pulse to a value smaller than that of the signal light pulse. The optical waveguide portion of the non-linear optical waveguide,is formed of a non-linear optical medium of which the non-linear refractive index changes due to absorption or amplification of the controlling light. The frequency &ohgr;,of the signal light is set to the transparent region of the non-linear optical waveguide,When the frequency &ohgr;,of the controlling light is set to the absorption region of the non-linear optical waveguide,some of signal light pulses incident together with the controlling lights partially frequency-shift toward the high-frequency area. The optical frequency filter,outputs only the frequency-shifted components. This allows the optical switching operation to be realized by controlling light pulses with low energies.