Energy system monitoring

Patent metadata

Field	Value
Publication number	US-9677916-B2
Application number	US-201414331318-A
Country	US
Kind code	B2
Filing date	Jul 15, 2014
Priority date	Jul 15, 2014
Publication date	Jun 13, 2017
Grant date	Jun 13, 2017

Abstract

An optical coupler includes at least one input waveguide and a plurality of output waveguides. The optical coupler spatially disperses optical signals carried on the input waveguide according to wavelength to the output waveguides. The input waveguides and the output waveguides are arranged to provide crosstalk between optical signals carried on the output waveguides.

First claim

The invention claimed is:

1. A monitoring system for an energy system, comprising:
N>1 optical sensors, each optical sensor operating within a different wavelength range and emanating output light in response to input light, the output light having a centroid wavelength that changes in response to a sensed parameter of the energy system;
a plurality of photodetectors, each photodetector configured to generate an electrical signal in response to light incident on a light sensitive surface of the photodetector; and

an optical coupler including at least one input waveguide configured to receive light from the optical sensors and a plurality of output waveguides, the optical coupler configured to disperse light from the input waveguide to the output waveguides according to wavelength of light so that sensor output light emanating from each optical sensor is optically coupled through at least one output waveguide to at least one photodetector, wherein the electrical signal generated by the photodetector in response to the sensor output light provides information about the sensed parameter of the energy system, wherein:
the plurality of output waveguides comprises N pairs of output waveguides;
the plurality of photodetectors comprises N pairs of photodetectors; and
the optical coupler is configured to spatially disperse light from the input waveguide according to wavelength so that the output light emanating from each optical sensor is optically coupled to a pair of photodetectors through a pair of adjacent output waveguides and the output waveguides in the pair are arranged and configured to allow crosstalk between the pair of output waveguides.

2. The system of claim 1 , wherein the optical coupler comprises an arrayed waveguide grating.

3. The system of claim 1 , wherein the optical coupler comprises a linear variable filter.

4. The system of claim 1 , wherein the N pairs of output waveguides are configured so that the crosstalk between the output waveguides of the pair of output waveguides is greater than crosstalk between either of the output waveguides of the pair and a waveguide of an adjacent pair.

5. The system of claim 1 , further comprising at least one additional optically dispersive element between the optical coupler and the photodetectors.

6. The system of claim 1 , wherein the optical coupler comprises an arrayed waveguide grating having at least N output waveguides, each output waveguide having a wavelength pass-band at least equal to a range of an expected spectral shift of output light of an associated optical sensor.

7. The system of claim 1 , further comprising processor circuitry configured to perform an estimation routine using the electrical signals to locate centroids of output light emanating from the N sensors.

8. The system of claim 1 , wherein the N optical sensors are arranged along a single sensor waveguide.

9. The system of claim 1 , wherein the energy device is a battery.

10. The system of claim 1 , wherein the photodetectors and optical coupler are arranged on a wafer as an integrated electro-optical subsystem.

11. The system of claim 1 , wherein the N optical sensors are disposed on multiple sensor waveguides, and further comprising an optical multiplexer optically coupled between the multiple sensor waveguides and the input waveguide.

12. The system of claim 1 , wherein the output waveguides are adjacent and a center-to-center spacing between the adjacent output waveguides in the pair of output waveguides is on the order of a full width half maximum intensity (FWHM) optical spot size at an input of the output waveguides.

13. The system of claim 11 , wherein the optical multiplexer comprises a wavelength division multiplexer.

14. The system of claim 12 , wherein the spacing is between about ⅕ and about 5 times the FWHM optical spot size at the input of the output waveguides.

15. The system of claim 12 , wherein the spacing is between about ½ and about 2 times the FWHM optical spot size at the input of the output waveguides.

16. A monitoring system for an energy system, comprising:
N>1 optical sensors, each optical sensor operating within a different wavelength range and emanating output light in response to input light, the output light having a centroid wavelength that changes in response to a sensed parameter of the energy system;
a plurality of photodetectors, each photodetector configured to generate an electrical signal in response to light incident on a light sensitive surface of the photodetector; and

an optical coupler including at least one input waveguide configured to receive light from the optical sensors and a plurality of output waveguides, the optical coupler configured to disperse light from the input waveguide to the output waveguides according to wavelength of light so that sensor output light emanating from each optical sensor is optically coupled through at least one output waveguide to at least one photodetector, wherein the electrical signal generated by the photodetector in response to the sensor output light provides information about the sensed parameter of the energy system,
wherein the optical coupler comprises an arrayed waveguide grating including K array waveguides optically coupled to the input waveguide, wherein K is chosen according to the formula

λ

m
⁢

⁢
Δλ

≤
K
≤

4
⁢
λ

m
⁢

⁢
Δλ

,

Δλ is an expected operational range of the sensor with a center wavelength λ, and m is a diffraction order of the AWG.

17. A monitoring system for an energy system, comprising:
N>1 optical sensors, each optical sensor operating within a different wavelength range and emanating output light in response to input light, the output light having a centroid wavelength that changes in response to a sensed parameter of the energy system;
a plurality of photodetectors, each photodetector configured to generate an electrical signal in response to light incident on a light sensitive surface of the photodetector; and
an optical coupler including at least one input waveguide configured to receive light from the optical sensors and a plurality of output waveguides, the optical coupler configured to disperse light from the input waveguide to the output waveguides according to wavelength of light so that sensor output light emanating from each optical sensor is optically coupled through at least one output waveguide to at least one photodetector, wherein the electrical signal generated by the photodetector in response to the sensor output light provides information about the sensed parameter of the energy system,
wherein the optical coupler comprises an arrayed waveguide grating including K array waveguides optically coupled to the input waveguide, the K array waveguides spaced a distance d apart, each array waveguide arranged a distance f from an input of an output

Assignees

• Palo Alto Res Ct Inc

Inventors

• Hegyi Alex
• Kiesel Peter
• Raghavan Ajay

Classifications

• G02B6/12009

  comprising arrayed waveguide grating [AWG] devices, i.e. with a phased array of waveguides · CPC title

• G02B6/2938

  for multiplexing or demultiplexing, i.e. combining or separating wavelengths, e.g. 1xN, NxM · CPC title

• G01D5/35383 Primary

  using multiple sensor devices using multiplexing techniques · CPC title

• G01R31/3606

  Physics · mapped topic

• G01N2201/088

  Using a sensor fibre · CPC title