公开(公告)号：US20230031468A1

公开(公告)日：2023-02-02

申请号：US17961004

申请日：2022-10-06

Applicant: Huawei Technologies Co., Ltd.

Inventor： Chao Pan ,  Ziliang Li ,  Ning Deng

IPC: G01M11/00 ,  H04B10/071

Abstract: An optical time-domain reflectometer (OTDR), where a laser emitting apparatus of the OTDR outputs a first optical signal in a first time period. A signal modulation apparatus of the OTDR generates a pulse signal based on the first optical signal, and outputs the pulse signal to an optical fiber in a second time period, where the first time period includes the second time period. A receiver of the OTDR receives a scattered signal from the optical fiber, where a frequency of the scattered signal is the same as a frequency of the first optical signal. Then, the laser emitting apparatus outputs a second optical signal in a third time period, where a frequency of the second optical signal is different from the frequency of the first optical signal. The second optical signal is used as a local oscillator signal to implement coherent detection in the receiver.

公开(公告)号：US12181370B2

公开(公告)日：2024-12-31

申请号：US17961004

申请日：2022-10-06

Applicant: Huawei Technologies Co., Ltd.

Inventor： Chao Pan ,  Ziliang Li ,  Ning Deng

IPC: G01M11/00 ,  H04B10/071

Abstract: An optical time-domain reflectometer (OTDR), where a laser emitting apparatus of the OTDR outputs a first optical signal in a first time period. A signal modulation apparatus of the OTDR generates a pulse signal based on the first optical signal, and outputs the pulse signal to an optical fiber in a second time period, where the first time period includes the second time period. A receiver of the OTDR receives a scattered signal from the optical fiber, where a frequency of the scattered signal is the same as a frequency of the first optical signal. Then, the laser emitting apparatus outputs a second optical signal in a third time period, where a frequency of the second optical signal is different from the frequency of the first optical signal. The second optical signal is used as a local oscillator signal to implement coherent detection in the receiver.