Optical fiber characteristic measuring device, optical fiber characteristic measuring method, and variable optical delay device
AssigneeYokogawa Electric Corporation
InventorsYuta SUZUKI, Masayoshi HONMA, Shin-ichirou TEZUKA
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Abstract
An optical fiber characteristic measuring device includes a light source configured to emit laser light modulated at a predetermined modulation frequency, a photodetector configured to detect Brillouin scattered light obtained by causing the laser light to be incident on a measurement target optical fiber, and a control unit configured to perform control to change a position of a correlation peak by adjusting an amount of delay of the laser light used for detecting the laser light incident on the measurement target optical fiber or the Brillouin scattered light without changing the modulation frequency.
Claims12
An optical fiber characteristic measuring device comprising:
- a light source configured to emit laser light modulated at a predetermined modulation frequency;
- a photodetector configured to detect Brillouin scattered light obtained by causing the laser light to be incident on a measurement target optical fiber;
- and
- a control unit configured to perform control to change a position of a correlation peak by adjusting an amount of delay of the laser light used for detecting the laser light incident on the measurement target optical fiber or the Brillouin scattered light without changing the modulation frequency.
An optical fiber characteristic measuring method comprising:
- a step of emitting laser light modulated at a predetermined modulation frequency;
- a step of detecting Brillouin scattered light obtained by causing the laser light to be incident on a measurement target optical fiber;
- and
- a step of performing control to change a position of a correlation peak by adjusting an amount of delay of the laser light used for detecting the laser light incident on the measurement target optical fiber or the Brillouin scattered light without changing the modulation frequency.
A variable optical delay device comprising:
- n (n is an integer equal to or larger than 2) modules subjected to cascade connection with a switchable amount of delay of light,
- wherein each of the modules comprises:
- p (p is an integer equal to or larger than 2) optical fibers having lengths different from each other;
- and
- an optical switch configured to switch the optical fiber of the p optical fibers allowing light to pass therethrough, and
- wherein when a predetermined reference length is Δz, an optical path length L(i,j) of the jth (j is an integer satisfying 0≤j≤p−1) optical fiber provided in the ith (i is an integer satisfying 0≤i≤n−1) module is expressed by the following expression.
- L
-
- (
- i
- ,
- j
- )
- =
- p
- i
- ·
- j
- ·
- Δ
-
- z
- +
- L
-
- (
- i
- ,
- 0
- )
Dependencies are inferred from the claim text.