Patent ID: 7504618

Claim:
A method of performing distributed sensing with an optical fiber using Brillouin scattering, comprising: transmitting a light pulse into the optical fiber, wherein the transmitted light pulse has a first frequency; combining backscattered light and optical local oscillator light, wherein the backscattered light is received from the optical fiber in response to the transmitted light pulse, and wherein the optical local oscillator light has a second frequency; causing a frequency offset to be present between the first frequency of the transmitted light pulse and the second frequency of the optical local oscillator light, wherein the frequency offset is at least 1 GHz less than a Brillouin frequency shift of the backscattered light; acquiring spectra representing Stokes and anti-Stokes components of the backscattered light, wherein the Stokes and anti-Stokes components are separated by a frequency span that is based on the frequency offset; and outputting representations of the Stokes and anti-Stokes components to enable display of the Stokes and anti-Stokes components.