Passive, temperature compensated techniques for tunable filter calibration in bragg-grating interrogation systems
US6744035B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 17, 2003 |
| Grant date | Jun 1, 2004 |
| Priority date | — |
| Expiry date | Mar 15, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/02204
- WIPO fieldOptics
- WIPO sectorInstruments
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.