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:
Feb. 18, 2003
Filed:
Aug. 14, 2001
Tzu-Yih Chu, San Jose, CA (US);
Shyang Chang, Hacienda, CA (US);
Chi Au, Union City, CA (US);
Abraham C. Ma, Fremont, CA (US);
Super Light Wave Corp., San Jose, CA (US);
Abstract
Optical logic gates are constructed from Mach-Zehnder Interferometer (MZI) optical circuits. A multi-mode interference (MMI) splitter divides a continuous-wave input into two branches of the interferometer. Each branch has a semiconductor optical amplifier (SOA). When a logic input having a logic-high power level is applied to one of the SOA's, cross-phase modulation occurs in the SOA. The phase shift increases through the SOA. The branch coupled to the logic input has a relative phase shift of &pgr; compared with the other branch. When two branches with the &pgr; phase difference are combined, destructive interference occurs, producing a logic low. An MMI combiner or an equivalent phase shifter is used to combine the two branches. The MMI splitter adds a phase shift of &pgr;/ to the upper branch but not to the lower branch, while the MMI combiner also adds &pgr;/ shifts.