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:
Jun. 01, 2004
Filed:
Jan. 17, 2003
Gregg A. Johnson, Fairfax, VA (US);
Bryan L. Althouse, Annapolis, MD (US);
Greg Nau, Alexandria, VA (US);
Sandeep T. Vohra, Fairfax Station, VA (US);
The United States of America as represented by the Secretary of the Navy, Washington, DC (US);
Abstract
A passive, temperature compensated tunable filter calibration device in a Bragg-grating interrogation system. The invention comprises two systems: 1) a dual substrate Bragg grating calibration system, the temperature of an array of gratings is estimated using an array of gratings bonded to a common host substrate and a single grating bonded to a material with a different coefficient of thermal expansion; 2) a hydrogen cyanide wavelength reference absorption cell that absorbs light at discrete wavelengths corresponding to the molecular vibration mode frequencies of the gas. A first photodetector sees the transmission spectrum and a second sees the reflections from Bragg gratings in a sensing array. In this system there is no temperature compensation step as the absorption lines are not sensitive to temperature.