Reduction of laser frequency noise and intensity noise in phase-shifted fiber bragg grating acoustic-emission sensor system

Lingling Hu, Ming Han

Research output: Contribution to journalArticlepeer-review

5 Scopus citations

Abstract

The noise performance of a fiber-optic acoustic-emission (AE) sensor system is often limited by the laser intensity noise and the laser frequency noise. Here, we report a novel low-cost, high-performance noise reduction method for fiber-optic AE sensor system based on a π-phase-shifted fiber Bragg grating. This method uses a reference channel built by an all-fiber Michelson interferometer formed by a 3×3 fiber-optic coupler and two Faraday mirrors. The reference channel has two outputs whose spectra are two sinusoidal fringes with a relative phase shift of 2π/3. A novel signal processing method is developed to extract both the laser intensity noise and the laser frequency noise from the outputs of the reference channel, which are subsequently removed from the output of the sensing channel. The results show that, for an AE sensor system using a distributed-feedback semiconductor laser as the laser source, this method achieves a noise reduction ratio of more than 20 dB. The reference channel possesses a broad operating spectral width and has the potential to be used in a multiplexed AE sensor system.

Original languageEnglish (US)
Article number7950902
Pages (from-to)4820-4825
Number of pages6
JournalIEEE Sensors Journal
Volume17
Issue number15
DOIs
StatePublished - Aug 1 2017

Keywords

  • Fiber-optic sensors
  • diode lasers
  • fiber gratings
  • nondestructive testing

ASJC Scopus subject areas

  • Instrumentation
  • Electrical and Electronic Engineering

Fingerprint Dive into the research topics of 'Reduction of laser frequency noise and intensity noise in phase-shifted fiber bragg grating acoustic-emission sensor system'. Together they form a unique fingerprint.

Cite this