Optical fiber sensing system with reduced spatial resolution and noise for multiple application uses

US11391622B2 · kind B2 · utility

Assignee

• NEC CORPORATION · JP

Inventors

• Ezra Ip · Princeton Colonial Park, US
• Yue-Kai Huang · Princeton, US
• Junqiang Hu · Davis, US
• Philip Nan Ji · Cranbury, US
• Shuji Murakami · Shizuoka, JP
• Yaowen Li · Hyattsville, US

Key dates

• Filing date: Feb 5, 2020
• Grant date: Jul 19, 2022
• Expiry date: Feb 18, 2040

Classification

• Technology area (CPC G): Physics
• CPC primary: G01H9/004
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An optical fiber sensing system with reduced spatial resolution and noise for multiple applications and method of operating same that employs a coherent receiver configured to detect and digitize both I and Q signals in two polarizations and performs signal beating in a digital signal processor (DSP) using the polarization-diverse signals to obtain beating results for multiple polarization state pairs that effectively reduces polarization induced fading effect(s) while providing faster sensing speed(s) and more efficient filtering. Since Rayleigh signals are captured in two orthogonal polarizations, four beating products are determined at once in the DSP and all are used for fiber strain determination thereby avoiding polarization fading.