US 10,871,406 B2 · Optical fiber strain and temperature measurement apparatus and optical fiber strain and temperature measurement method

Abstract

A self-delayed homodyne interferometer includes light source unit, a splitting unit, an interference signal acquisition unit, a scattered light intensity acquisition unit, and a signal processing unit. The light source unit generates probe light. The splitting unit splits into two branches, Brillouin backscattered light occurring in an optical fiber to be measured with the probe light. The acquisition unit receives scattered light of one branch, and uses a self-delayed homodyne interferometer to generate an interference signal. The acquisition unit receives scattered light of the other branch, and acquires intensity of the scattered light. The signal processing unit separates and acquires a frequency shift amount from the intensity of the interference signal, and strain and temperature change from the intensity of the scattered light. The acquisition unit can change a phase of the scattered light of the one of the two branches.

Claims8

Dependent claims

An optical fiber strain and temperature measurement apparatus comprising:

a light source unit configured to generate probe light;
a splitting unit configured to split Brillouin backscattered light into two branches, the Brillouin backscattered light occurring in an optical fiber to be measured with the probe light;
an interference signal acquisition unit configured to receive scattered light of one of the two branches split by the splitting unit, and use self-delayed homodyne interferometer to generate an interference signal;
a scattered light intensity acquisition unit configured to receive scattered light of another of the two branches split by the splitting unit, and acquire intensity of the scattered light;
and
a signal processing unit configured to separate and acquire a frequency shift amount acquired from intensity of the interference signal, and strain δε and a temperature change δT from the intensity of the scattered light, wherein
the interference signal acquisition unit is capable of changing a phase of the scattered light of the one of the two branches.

4 more elements

An optical fiber strain and temperature measurement method comprising:

generating probe light;
splitting Brillouin backscattered light into two branches, the Brillouin backscattered light occurring in an optical fiber to be measured with the probe light;
splitting scattered light of one of the two branches into two branches of a first light path and a second light path;
providing delay to scattered light propagating through the first light path;
multiplexing the scattered light propagating through the first light path and scattered light propagating through the second light path to generate interfering light;
performing photoelectric conversion on the interfering light to generate an interference signal that is an electrical signal;
acquiring a frequency shift amount from intensity of the interference signal;
acquiring scattered light intensity from scattered light of another of the two branches into which the Brillouin backscattered light is split;
and
separating and acquiring strain δε and a temperature change δT from the frequency shift amount and the scattered light intensity.

7 more elements

Dependencies are inferred from the claim text.

Optical fiber strain and temperature measurement apparatus and optical fiber strain and temperature measurement method

Life of this patent

Optical fiber strain and temperature measurement apparatus and optical fiber strain and temperature measurement method

Life of this patent

Abstract

Claims8