Sensitivity characteristics of broadband fiber-laser-based ultrasound sensors for photoacoustic microscopy

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

17 Scopus Citations
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Author(s)

  • Xue Bai
  • Yizhi Liang
  • Huojiao Sun
  • Long Jin
  • Jun Ma
  • Bai-Ou Guan

Detail(s)

Original languageEnglish
Pages (from-to)17616-17626
Journal / PublicationOptics Express
Volume25
Issue number15
Online published13 Jul 2017
Publication statusPublished - 24 Jul 2017

Abstract

High-frequency fiber laser sensor is a new acoustic detector for photoacoustic imaging. However, its performance has not been thoroughly studied. Here, we present a comprehensive characterization of a fiber laser sensor for photoacoustic imaging. Ultrasound waves deform the fiber laser cavity and induce frequency changes in the heterodyning output signal. The sensitivity peaks at 22 MHz, which is associated with an azimuthal mode number l = 2 and a radial mode number n = 1. The broadband acoustic sensitivity in terms of frequency shift is 2.25 MHz/kPa and the noise-equivalent pressure reaches 45 Pa with a sampling rate of 100 MHz. The 3-dB bandwidth is 18 MHz for spherical-wave detection. We characterized the spatial distribution of acoustic sensitivity. The sensitivity along the fiber longitudinal direction varies with the laser spatial mode and is determined by the grating and cavity parameters. The sensitivity at the azimuthal direction presents a |cos(2θ)| dependence as a result of fiber core asymmetry. In the radial direction, the sensitivity is inversely proportional to the square root of the distance between the source and the detector. The acoustic sensitivity can be enhanced by reducing the cavity length. We experimentally show that a short sensor can enhance the contrast and penetration depth of PAM than a long one.

Citation Format(s)

Sensitivity characteristics of broadband fiber-laser-based ultrasound sensors for photoacoustic microscopy. / Bai, Xue; Liang, Yizhi; Sun, Huojiao; Jin, Long; Ma, Jun; Guan, Bai-Ou; Wang, Lidai.

In: Optics Express, Vol. 25, No. 15, 24.07.2017, p. 17616-17626.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review