Optical measurement system

An optical measurement system comprising:

• a coherent light source configured to generate a light signal;
• a launch stage configured to receive the light signal from the light source and generate a pulsed test signal and launch the test signal along an optical path, wherein the test signal comprises a first test signal component and a second test signal component which is frequency-shifted relative to the first test signal component;
• a local oscillator stage configured to generate a local oscillator signal;
• and
• a first detector stage configured to:
• receive the local oscillator signal from the local oscillator stage and a scattered signal from the optical path, wherein the scattered signal comprises a Rayleigh scattering component resulting from scattering of the first test signal component and a Brillouin scattering component resulting from scattering of the second test signal component;
• and
• interfere the local oscillator signal with the scattered signal to produce an output signal having a first component at a first frequency corresponding to a frequency difference between the local oscillator signal and the Rayleigh scattering component, and a second component at a second frequency corresponding to a frequency difference between the local oscillator signal and the Brillouin scattering component.

An optical measurement system comprising:

• a coherent light source configured to generate a light signal;
• a launch stage configured to receive the light signal from the light source and generate a pulsed test signal and launch the test signal along an optical path;
• a local oscillator stage configured generate a local oscillator signal;
• a first detector stage and a second detector stage;
• and
• a wavelength splitter configured to receive a scattered signal from the optical path, and split the scattered signal into a first scattering component which is transmitted to the first detector stage and a Raman scattering component which is transmitted to the second detector stage;
• wherein the first detector stage is configured to interfere the local oscillator signal with the scattered signal to produce an output signal having a frequency corresponding to a frequency difference between the local oscillator signal and the first scattering component;
• wherein the second detector stage is configured to split the Raman scattering component into a Stokes component and an Anti-Stokes component, and to detect an amplitude of each of the Stokes component and the Anti-Stokes component.

A method for operating an optical measurement system, the method comprising:

• generating, using a coherent light source, a light signal, and conveying the light signal to a launch stage;
• generating, at the launch stage, a pulsed test signal and launching the test signal along an optical path;
• generating, at a local oscillator stage, a local oscillator signal, wherein local oscillator signal comprises a first local oscillator component and a second local oscillator component which is frequency-shifted relative to the first local oscillator component;
• receiving, at a first detector stage, the local oscillator signal from the local oscillator stage and a scattered signal from the optical path, wherein the scattered signal comprises a Rayleigh scattering component and a Brillouin scattering component;
• and
• interfering, by the first detector stage, the local oscillator signal with the scattered signal to produce an output signal having a first component at a first frequency corresponding to a frequency difference between the first local oscillator component and the Rayleigh scattering component, and a second component at a second frequency corresponding to a frequency difference between the second local oscillator component and the Brillouin scattering component.

A method for operating an optical measurement system, the method comprising:

• generating, using a coherent light source, a light signal, and conveying the light signal to a launch stage;
• generating, at the launch stage, a pulsed test signal and launching the test signal along an optical path, wherein the test signal comprises a first test signal component and a second test signal component which is frequency-shifted relative to first test signal component;
• generating, at a local oscillator stage, a local oscillator signal;
• receiving, at a first detector stage, the local oscillator signal from the local oscillator stage and a scattered signal from the optical path, wherein the scattered signal comprises a Rayleigh scattering component resulting from scattering of the first test signal component and a Brillouin scattering component resulting from scattering of the second test signal component;
• and
• interfering, by the first detector stage, the local oscillator signal with the scattered signal to produce an output signal having a first component at a first frequency corresponding to a frequency difference between the local oscillator signal and the Rayleigh scattering component, and a second component at a second frequency corresponding to a frequency difference between the local oscillator signal and the Brillouin scattering component.

A method for operating an optical measurement system, the method comprising:

• generating, using a coherent light source, a light signal, and conveying the light signal to a launch stage;
• generating, at the launch stage, a pulsed test signal and launching the test signal along an optical path;
• generating, at a local oscillator stage, a local oscillator signal;
• receiving, at a wavelength splitter, a scattered signal from the optical path, and splitting the scattered signal into a first scattering component which is transmitted to a first detector stage and a Raman scattering component which is transmitted to a second detector stage;
• interfering, at the first detector stage, the local oscillator signal with the scattered signal to produce an output signal having a frequency corresponding to a frequency difference between the local oscillator signal and the first scattering component;
• and
• splitting, at the second detector stage, the Raman scattering component into a Stokes component and an Anti-Stokes component, and detecting an amplitude of each of the Stokes component and the Anti-Stokes component.