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, 2012
Filed:
Jun. 18, 2009
Christopher W. Smelser, Ottawa, CA;
Stephen J. Mihailov, Kanata, CA;
Dan Grobnic, Ottawa, CA;
Ping LU, Ottawa, CA;
Robert B. Walker, Spencerville, CA;
Gino Cuglietta, Kanata, CA;
Haimin Ding, Nepean, CA;
Xiaoli Dai, Ottawa, CA;
Christopher W. Smelser, Ottawa, CA;
Stephen J. Mihailov, Kanata, CA;
Dan Grobnic, Ottawa, CA;
Ping Lu, Ottawa, CA;
Robert B. Walker, Spencerville, CA;
Gino Cuglietta, Kanata, CA;
Haimin Ding, Nepean, CA;
Xiaoli Dai, Ottawa, CA;
Abstract
A method of producing a thermally stable grating allows the grating to be placed in environments where temperatures reach 1000° C. and where the grating is relatively stable and has very low loss from scatter. These gratings have spectral characteristics that allow them to be concatenated so as to form a sensor array. The method requires a step of lowering the characteristic intensity threshold of a waveguide by at least 25%, followed by irradiating the waveguide with femtosecond pulses of light having a sufficient intensity and for a sufficient duration to write the grating so that at least 60% of the grating remains after exposures of at least 10 hours at a temperature of at least 1000° C. Pre-writing a Type I grating before writing a minimal damage Type II grating lowers the characteristic threshold of the waveguide so that a stable low damage type II grating can be written; alternatively providing a hydrogen or deuterium loaded waveguide before writing the grating lowers the characteristic threshold of the waveguide.