Optical source for optical sensing system
First Claim
1. An optical source for use in an optical sensing system, for producing an optical interrogation signal comprising a plurality of component signals, each component signal comprising light in a wavelength band different from the wavelength bands of the other component signals, the optical source comprising:
- a concave diffraction grating;
means for forming an aperture at which the interrogation signal will be formed, the aperture having an aperture diameter; and
a plurality of optical emitters, each emitter producing an emitter signal having a bandwidth, each emitter being positioned such that the emitter signal produced by the emitter strikes the concave diffraction grating, and is focused into a focal spot at the aperture, such that a portion of the emitter signal enters the aperture and forms one of the component signals, each focal spot having a focal spot diameter, the bandwidths of the emitter signals and the aperture diameter being selected such that each focal spot diameter exceeds the aperture diameter, such that the range of wavelengths of each emitter signal that enters the aperture is less than the bandwidth of the emitter signal.
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Accused Products
Abstract
An optical source for use in an optical sensing system such as a wavelength division multiplexing system. The source produces an optical interrogation signal comprising a plurality of component signals, each component signal comprising light in a wavelength band different from the wavelength bands of the other component signals. The source comprises a concave diffraction grating, means for forming an aperture at which the interrogation signal will be formed, and a plurality of optical emitters. Each emitter is positioned such that the emitter output signal strikes the concave diffraction grating, and is focused onto the aperture, such that a portion of the emitter signal enters the aperture and forms one of the component signals. As a result, the component signal wavelengths are not sensitive to temperature-induced fluctuations in the emitter output signal.
46 Citations
10 Claims
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1. An optical source for use in an optical sensing system, for producing an optical interrogation signal comprising a plurality of component signals, each component signal comprising light in a wavelength band different from the wavelength bands of the other component signals, the optical source comprising:
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a concave diffraction grating; means for forming an aperture at which the interrogation signal will be formed, the aperture having an aperture diameter; and a plurality of optical emitters, each emitter producing an emitter signal having a bandwidth, each emitter being positioned such that the emitter signal produced by the emitter strikes the concave diffraction grating, and is focused into a focal spot at the aperture, such that a portion of the emitter signal enters the aperture and forms one of the component signals, each focal spot having a focal spot diameter, the bandwidths of the emitter signals and the aperture diameter being selected such that each focal spot diameter exceeds the aperture diameter, such that the range of wavelengths of each emitter signal that enters the aperture is less than the bandwidth of the emitter signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An optical source for use in an optical sensing system, for producing an optical interrogation signal comprising a plurality of component signals, each component signal comprising light in a wavelength band different from the wavelength bands of the other component signals, the optical source comprising:
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a concave diffraction grating; means for forming an aperture at which the interrogation signal will be formed; and a plurality of optical emitters, each emitter producing an emitter signal having a bandwidth, each emitter being positioned such that the emitter signal produced by the emitter strikes the concave diffraction grating, and is focused into a focal spot at the aperture, such that a portion of the emitter signal enters the aperture and forms one of the component signals, each focal spot having a focal spot diameter, the bandwidths of the emitter signals and the aperture diameter being selected such that each focal spot diameter exceeds the aperture diameter, such that the range of wavelengths of each emitter signal that enters the aperture is less than the bandwidth of the emitter signal each emitter comprising an LED and a fiber-optic cable associated with the LED, each fiber-optic cable having a first end positioned to receive light from the associated LED, and a second end positioned in a focal plane of the grating. - View Dependent Claims (10)
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Specification