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:
Feb. 20, 2001
Wei-Ping Huang, Ancaster, CA;
Chenglin Xu, Burlington, CA;
Mee Koy Chin, Wilmette, IL (US);
Yi Liang, Burlington, CA;
Xun Li, Waterloo, CA;
LNL Technologies, Inc., Cambridge, MA (US);
Abstract
A strongly confined ridge waveguide that provides substantially reduced polarization sensitivity, without significant compromise for other waveguide characteristics such as, for example, single-mode condition, and low propagation and bending losses for the fundamental mode. The present invention considers waveguide material composition and thickness for guiding and cladding layers, bend radius, ridge width and etch depth at which the modal indices of the fundamental TE and TM modes are equal. With those parameters, the losses (e.g., the imaginary parts of the modal indices) of the fundamental and first-order modes may be calculated. By considering the previously mentioned criteria, a low-loss, single-mode ridge waveguide may be constructed in accordance with the present invention having losses of the fundamental modes in the range of less than approximately 1.0 dB/mm, and losses of higher-order modes in the range of greater than approximately 10 dB/mm (thus providing a loss difference of at least approximately 10 dB/mm).