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:
Apr. 11, 2000
Filed:
Oct. 09, 1997
Shigeru Nakamura, Tokyo, JP;
Kazuhito Tajima, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
An optically controlled optical switch operating at a high speed and at a high efficiency can be realized with a simple construction. An optical signal exiting from a nonlinear optical waveguide is passed through an optical frequency filter and then guided into an optical output signal port. The optical frequency filter is a band-pass filter for passing only optical signal pulses having a center frequency of .omega.1. Where the center frequency .omega.0 of controlling light is set within the absorption region of the nonlinear optical waveguide, optical controlling pulses are absorbed, and carriers are excited. This results in a change in the refractive index. Consequently, the center frequency .omega.1 of only the optical signal pulses entered simultaneously with the optical controlling pulses is shifted to .omega.2. The optical frequency filter blocks optical signal pulses whose center frequency has been shifted to .omega.2. Thus, a gate-type optical switching action is accomplished.