公开(公告)号：US20240393208A1

公开(公告)日：2024-11-28

申请号：US18670101

申请日：2024-05-21

Applicant: Yokogawa Electric Corporation

Inventor： Yuta Suzuki ,  Shin-ichirou Tezuka ,  Masayoshi Honma

IPC: G01M11/00

Abstract: An optical fiber characteristics measurement apparatus includes a first optical splitter that splits modulated light into pump light and reference light, a second optical splitter that causes the pump light to be incident on a fiber under test from one end and extracts Brillouin scattered light generated within the fiber under test, an adjuster that changes frequency of at least one of the reference light and pump light to a plurality of frequencies, and a calculator that measures characteristics of the fiber under test based on a second harmonic component among frequency components of a signal yielded by homodyne detection of interference light between the Brillouin scattered light and the reference light at each frequency, the second harmonic component having a frequency that is two times the modulation frequency of the modulated light.

公开(公告)号：US11650155B2

公开(公告)日：2023-05-16

申请号：US17390074

申请日：2021-07-30

Applicant: YOKOGAWA ELECTRIC CORPORATION

Inventor： Yuta Suzuki ,  Yuma Kitagawa ,  Toshiyuki Saruya ,  Nobuhiko Kanbara

IPC: G01N21/61

CPC classification number: G01N21/61 ,  G01N2201/068 ,  G01N2201/0612 ,  G01N2201/121

Abstract: A gas analysis system, includes: a light-emitting element that emits a laser light modulated by a predetermined modulation frequency; and a light-receiving element that: receives the laser light that has passed through a measurement target gas; and upon receiving the laser light, outputs a received signal having an N-frequency that is n times the predetermined modulation frequency, wherein n is an integer no less than 2; and a signal processing device that: calculates a third component by removing, from a first component having the N-frequency, a second component, wherein the second component is a component of optical interference noise arising on an optical path of the laser light from the light-emitting element to the light-receiving element and has the same frequency as the first component; and calculates, based on a magnitude of the third component, a concentration of the measurement target gas.

公开(公告)号：US20220034807A1

公开(公告)日：2022-02-03

申请号：US17390074

申请日：2021-07-30

Applicant: YOKOGAWA ELECTRIC CORPORATION

Inventor： Yuta Suzuki ,  Yuma Kitagawa ,  Toshiyuki Saruya ,  Nobuhiko Kanbara

IPC: G01N21/61

Abstract: A gas analysis system, includes: a light-emitting element that emits a laser light modulated by a predetermined modulation frequency; and a light-receiving element that: receives the laser light that has passed through a measurement target gas; and upon receiving the laser light, outputs a received signal having an N-frequency that is n times the predetermined modulation frequency, wherein n is an integer no less than 2; and a signal processing device that: calculates a third component by removing, from a first component having the N-frequency, a second component, wherein the second component is a component of optical interference noise arising on an optical path of the laser light from the light-emitting element to the light-receiving element and has the same frequency as the first component; and calculates, based on a magnitude of the third component, a concentration of the measurement target gas.

公开(公告)号：US20250052641A1

公开(公告)日：2025-02-13

申请号：US18795616

申请日：2024-08-06

Applicant: Yokogawa Electric Corporation

Inventor： Yuta Suzuki ,  Shin-ichirou Tezuka ,  Masayoshi Honma

IPC: G01M11/00

Abstract: An optical fiber characteristics measurement apparatus (10) according to the present disclosure measures the characteristics of an optical fiber. The optical fiber characteristics measurement apparatus (10) includes a laser light source module (11) that outputs frequency-modulated laser light. The laser light source module (11) includes a laser light source (110) that outputs laser light, a laser light source driver (111) that modulates the frequency of the laser light outputted by the laser light source (110), and an optical amplifier (116) that adjusts the amplitude of the frequency-modulated laser light outputted by the laser light source (110) so as to cancel an amplitude modulation occurring in the frequency-modulated laser light outputted by the laser light source (110).

公开(公告)号：US20240426702A1

公开(公告)日：2024-12-26

申请号：US18739798

申请日：2024-06-11

Applicant: Yokogawa Electric Corporation

Inventor： Yuta Suzuki ,  Shin-ichirou Tezuka ,  Masayoshi Honma

IPC: G01M11/00

Abstract: An optical fiber characteristic measurement apparatus includes an arithmetic unit configured to measure the characteristic of an optical fiber under test by extracting multiple peaks in a Brillouin gain spectrum of Brillouin scatted light occurring in the optical fiber under test.