Bragg grating sensor system with spectral response or code division multiplexing

• US 6,489,606 B1
• Filed: 04/07/2000
• Issued: 12/03/2002
• Est. Priority Date: 04/07/2000
• Status: Expired due to Term

• Current Assignee: Illumina Incorporated
• Original Assignee: Cidra Sarl (Nordic Cultural & Educational Foundation)
• Inventors: Dunphy, James R., Kersey, Alan D., Rubino, Robert A.
• Primary Examiner(s): PYO, KEVIN K
• Application Number:
  US09/545,792
• Time in Patent Office: 970 Days
• Field of Search: 250/227.14, 250/227.16, 250/227.18, 250/227.19, 250/227.23, 356/32, 356/35.5, 385/12, 385/13, 385/37, 738/00
• US Class Current: 250/227.14
• CPC Class Codes: G01D 5/35303 using a reference fibre, e.g. interferometric devices
• CPC Class Codes: G01D 5/35316 using a Bragg gratings
• CPC Class Codes: G01D 5/35354 Sensor working in reflection
• CPC Class Codes: G01L 1/246 using integrated gratings, e.g. Bragg gratings
• CPC Class Codes: G02B 6/2932 comprising a directional router, e.g. directional coupler, circulator

Abstract

The present invention provides a sensor system for sensing a parameter, comprising an optical source, coupler and signal processor system in combination with multiple structured fiber Bragg gratings. The optical source, coupler and signal processor system provide an optical source signal to the multiple structured fiber Bragg gratings. The optical source, coupler and signal processor system also responds to multiple structured fiber Bragg grating signals, for providing an optical source, coupler and signal processor system signal containing information about a sensed parameter. The multiple structured fiber Bragg gratings respond to the optical source signal, and further respond to the sensed parameter, for providing the multiple structured fiber Bragg grating signals containing information about a complex superposition of spectral responses or codes related to the sensed parameter. Each of the multiple structured fiber Bragg gratings includes a respective broadband spectral response or code related to the sensed parameter.

Claims

1. A sensor system for sensing a parameter, comprising:

an optical source, coupler and signal processor system, for providing an optical source signal, responsive to multiple structured fiber Bragg grating signals, for providing an optical source, coupler and signal processor system containing information about a sensed parameter; and

multiple structured fiber Bragg gratings, responsive to the optical source signal, and further responsive to the sensed parameter, for providing the multiple structured fiber Bragg grating signals containing information about a complex superposition of spectral responses or codes related to the sensed parameter.

2. A sensor system according to claim 1,

wherein each of the multiple structured fiber Bragg gratings includes a respective broadband spectral response or code related to the sensed parameter.

3. A sensor system according to claim 1,

wherein the optical source, coupler and signal processing system includes a broadband light source, a coupler, a wavelength detection system and a correlation system;

wherein the broadband light source provides the optical source signal;

wherein the coupler responds to the optical signal, for providing a coupled optical signal to the multi-structured fiber Bragg gratings, and responds to the multiple structured fiber Bragg grating signals, for providing coupled multiple structured fiber Bragg grating signals;

wherein the wavelength detection system responds to the coupled multiple structured fiber Bragg grating signals, for providing a wavelength detection system signal containing information about a wavelength detection of the multiple structured fiber Bragg grating signals; and

wherein the correlation system responds to the wavelength detection system signal, for providing a correlation system signal containing information about the sensed parameter.

4. A sensor system according to claim 1,

wherein each of the multiple structured fiber Bragg gratings has a different spacing of a respective spectral component that is used to discriminate between the multiple structured fiber Bragg gratings.

5. A sensor system according to claim 4,

wherein the multiple structured fiber Bragg gratings are serially configured.

6. A sensor system according to claim 1,

wherein the optical source, coupler and signal processing system includes either a scanning filter or wavelength resolving instrument to detect a net spectral response from the multi-structured fiber Bragg gratings.

7. A sensor system according to claim 1, wherein each of the multiple structured fiber Bragg gratings has separate gratings with a unique broadband, multi-component, spectral response.

8. A sensor system according to claim 1,

wherein each of the multiple structured fiber Bragg gratings has separate gratings with a unique broadband, multi-component, spectral code.

9. A sensor system according to claim 1,

wherein each of the multiple structured fiber Bragg gratings has a respective noise code.

10. A sensor system according to claim 9,

wherein the respective noise code includes either maximal sequence codes or Gold codes.

11. A sensor system according to claim 3, wherein the wavelength detection system includes a scanning filter and a power detector, the scanning filter scanning for a particular wavelength for passing to the power detector.

12. A sensor system according to claim 1,

wherein the optical source, coupler and signal processing system includes a scanning laser, a coupler, a wavelength detection system and a correlation system;

wherein the scanning laser provides the optical source signal in the form of a scanning laser signal;

wherein the coupler responds to the scanning laser signal, for providing a coupled scanning laser signal to the multiple structured fiber Bragg gratings, and responds to the multiple structured fiber Bragg grating signals, for providing coupled multiple structured fiber Bragg grating signals;

wherein the wavelength detection system responds to the coupled multiple structured fiber Bragg grating signals, for providing a wavelength detection system signal containing information about a wavelength detection of the multiple structured fiber Bragg grating signals; and

wherein the correlation system responds to the wavelength detection system signal, for providing a correlation system signal containing information about the sensed parameter.

13. A sensor system according to claim 12, wherein the wavelength detection system comprises a detector that receives reflected wavelengths that are coincident with a respective multiple structured fiber Bragg grating in a time dependent fashion.

14. A sensor system for sensing a parameter having an optical source and a signal processor system,

characterized in that the sensor system comprises multiple structured fiber Bragg gratings that respond to an optical source signal from the optical source, and further respond to a sensed parameter, for providing multiple structured fiber Bragg grating signals containing information about a complex superposition of spectral responses or codes related to the sensed parameter.

15. A sensor system according to claim 14,

wherein each of the multiple structured fiber Bragg gratings includes a respective broadband spectral response or code related to the sensed parameter.

16. A sensor system according to claim 14,

wherein each of the multiple structured fiber Bragg gratings has a different spacing of a respective spectral component that is used to discriminate between the multiple structured fiber Bragg gratings.

17. A sensor system according to claim 16,

wherein the multiple structured fiber Bragg gratings are serially configured.

18. A sensor system according to claim 14,

wherein each of the multiple structured fiber Bragg gratings has separate gratings with a unique broadband, multi-component, spectral response.

19. A sensor system according to claim 14,

wherein each of the multiple structured fiber Bragg gratings has separate gratings with a unique broadband, multi-component, spectral code.

20. A sensor system according to claim 14,

wherein each of the multiple structured fiber Bragg gratings has a respective noise code.

21. A sensor system according to claim 20,

wherein the respective noise codes include either maximal sequence codes or Gold codes.