Claims
- 1. A passive, temperature compensated tunable filter calibration device in a Bragg-grating interrogation system comprised of:a calibration and reference device further comprised of an array of Bragg gratings bonded to a first host substrate and a single grating bonded to a second host substrate having a different linear coefficient of thermal expansion from that of the first host substrate; a plurality of gratings contained in an optical fiber forming a sensing array; a filter for filtering a broadband optical light so that at any point in time only a narrow band of light is present in the gratings containing fibers connected to the filter; a power source for applying a predetermined drive voltage to the scanning filter to produce a scanning filter control voltage; a first photodetector for receiving optical light reflected back from the calibration and reference device and converting the optical light to an electrical signal; a second photodetector for receiving light reflected from the sensing array an converting it to an electrical signal; amplifiers associated with each electrical signal amplifying the electrical signal representing the reflected light so as to show a series of peaks corresponding to the gratings in the array from the lowest to the highest wavelength as the drive voltage is increased; and processing electronics for receiving the amplified electrical signals and calculating a voltage-to-wavelength function for the scanning range of the filter.
- 2. A passive, temperature compensated tunable filter calibration device in a Bragg-grating interrogation system comprised of:a calibration and reference device further comprised of an array of Bragg gratings bonded to a first host substrate and a single grating bonded to a second host substrate having a different linear coefficient of thermal expansion from that of the first host substrate; a plurality of gratings contained in an optical fiber forming a sensing array; a filter for filtering a broadband optical light so that at any point in time only a narrow band of light is present in the gratings containing fibers connected to the filter; a power source for applying a predetermined drive voltage to the scanning filter to produce a scanning filter control voltage; a first means for receiving optical light reflected back from the calibration and reference device and converting the optical light to an electrical signal; a second means for receiving light reflected from the sensing array an converting it to an electrical signal; amplifiers associated with each electrical signal amplifying the electrical signal representing the reflected light so as to show a series of peaks corresponding to the gratings in the array from the lowest to the highest wavelength as the drive voltage is increased; and processing electronics for receiving the amplified electrical signals and calculating a voltage-to-wavelength function for the scanning range of the filter.
- 3. A device, as in claim 1, wherein the processing electronics is a computer.
- 4. A device, as in claim 1, wherein the processing electronics are an electrical circuit.
Parent Case Info
This is a continuation of Ser. No. 09/635,227 filed Aug. 9, 2000, now U.S. Pat. No. 6,573,489.
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Kind |
6118914 |
Davis et al. |
Sep 2000 |
A |
6310703 |
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B1 |
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Continuations (1)
|
Number |
Date |
Country |
Parent |
09/635227 |
Aug 2000 |
US |
Child |
10/346069 |
|
US |