Fiber optic sensor for detecting multiple parameters in a harsh environment

• US 8,180,185 B2
• Filed: 02/05/2008
• Issued: 05/15/2012
• Est. Priority Date: 03/22/2007
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Xia, Hua, Balasubramaniam, Mahadevan, Jiang, Jie, Luo, Huageng, Al-Khalidy, Abdul Rahman Abdallah, Young, Clayton Ming, McCarthy, Kevin Thomas
• Primary Examiner(s): Le, Uyen Chau N
• Assistant Examiner(s): CHU, CHRIS H
• Application Number:
  US12/026,229
• Publication Number:
  US 20110170823A1
• Time in Patent Office: 1,561 Days
• Field of Search: None
• US Class Current: 385/12
• 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 5/35341 Sensor working in transmission
• CPC Class Codes: G02B 6/021 characterised by the core or cladding or coating, e.g. materials, radial refractive index profiles, cladding shape
• CPC Class Codes: G02B 6/02138 based on illuminating a phase mask
• CPC Class Codes: G02B 6/02147 Point by point fabrication, i.e. grating elements induced one step at a time along the fibre, e.g. by scanning a laser beam, arc discharge scanning G02B6/02133 and G02B6/02142 take precedence
• CPC Class Codes: G02B 6/02185 based on treating the fibre, e.g. post-manufacture treatment, thermal aging, annealing annealing glass fibres C03B37/15
• CPC Class Codes: G02B 6/02209 Mounting means, e.g. adhesives, casings G02B6/02171 and G02B6/02195 take precedence

Abstract

A fiber optic sensor is provided. The fiber optic sensor includes a fiber core having a plurality of grating elements wherein, the grating elements comprise a periodic or a quasiperiodic modulated microcrystalline and silicon dioxide tetrahedral structure and a cladding disposed about the fiber core.

Claims

1. A fiber optic sensor, comprising:

a fiber core having a plurality of grating elements, wherein the grating elements comprise a periodic or a quasiperiodic modulated microcrystalline and silicon dioxide tetrahedral structure that is not over-constrained; and

a cladding disposed about the fiber core, wherein the fiber optic sensor comprises first and second claddings, and wherein the first cladding comprises a low-percentage fluorine or chlorine dopant and the second cladding comprises a relatively high-percentage fluorine or chlorine dopant.

2. The fiber optic sensor of claim 1, wherein the sensor is configured to simultaneously detect a plurality of parameters in a high or a dynamic temperature environment.

3. The fiber optic sensor of claim 2, wherein the sensor is configured to detect at least one parameter in a gas turbine, or a steam turbine, or a nuclear reactor vessel, or a combustion cell, or aircraft engines, or a coal-fired boiler, or combinations thereof.

4. The fiber optic sensor of claim 1, wherein the cladding comprises silicon dioxide with a fluorine dopant.

5. The fiber optic sensor of claim 1, further comprising;

an optical source configured to illuminate the fiber core; and

a detector module configured to detect at least one parameter based upon a reflection spectrum generated from the grating elements.

6. A distributed sensing system for sensing a plurality of parameters in an environment, comprising:

a plurality of sensors disposed on a distributed cable, wherein each of the plurality of sensors comprises;

a fiber core having a periodic or a quasiperiodic modulated microcrystalline and silicon dioxide tetrahedral grating structure that is not over-constrained; and

a cladding disposed about the fiber core, wherein the fiber optic sensor comprises first and second claddings, and wherein the first cladding comprises a low-percentage fluorine or chlorine dopant and the second cladding comprises a relatively high-percentage fluorine or chlorine dopant.

7. The distributed sensing system of claim 6, further comprising an optical source configured to illuminate the fiber core of each of the plurality of sensors.

8. The distributed sensing system of claim 7, wherein the optical source comprises a tunable laser.

9. The distributed sensing system of claim 7, further comprising an optical spectral analyzer configured to measure a parameter based on a wavelength spectrum from the distributed sensor system.