The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 02, 2024
Filed:
May. 06, 2022
Nanjing University, Nanjing, CN;
Yixin Zhang, Nanjing, CN;
Jinyu Song, Nanjing, CN;
Xuping Zhang, Nanjing, CN;
Zhewen Ding, Nanjing, CN;
Shuai Tong, Nanjing, CN;
Shun Wang, Nanjing, CN;
Feng Wang, Nanjing, CN;
NANJING UNIVERSITY, Nanjing, CN;
Abstract
A self-heterodyne phase-sensitive optical time domain reflectometry (φ-OTDR) system with a free multi-spatial resolution includes a narrow linewidth laser source, a 1×3 fiber-optic coupler, three acousto-optic modulators (AGMs), a 3×1 fiber-optic coupler, two time-delay fibers, an erbium-doped fiber amplifier (EDFA), a circulator, a photodetector, an electrical amplifier, three filters, a data acquisition card, a pulse signal generator, and a driver module. A plurality of acousto-optic modulators using the same driver are used to couple probe light with different pulse intervals and different frequency shifts and then inject the probe light into a fiber, such that a self-heterodyne detection structure with a multi-spatial resolution is implemented, which suppressed optical background noise such as coherent fading noise, phase noise introduced by a frequency drift of a light source, and pseudo-random noise (PRN).