Related Experiment Video
Updated: Jun 1, 2026
08:21
Wideband Optical Detector of Ultrasound for Medical Imaging Applications
Published on: May 11, 2014
High-sensitivity compact ultrasonic detector based on a pi-phase-shifted fiber Bragg grating
Amir Rosenthal1, Daniel Razansky, Vasilis Ntziachristos
1Institute for Biological and Medical Imaging (IBMI), Technical University of Munich and Helmholtz Center Munich, Ingoldstädter Landstrasse 1, 85764 Neuherberg, Germany. amir.rozental@helmholtz‐muenchen.de
Optics Letters
|May 20, 2011
Summary
A new fiber optic hydrophone uses a pi-phase-shifted fiber Bragg grating to detect ultrasonic fields with high sensitivity. This compact sensor is ideal for medical imaging like optoacoustic tomography.
Area of Science:
- Photonics and Optical Sensing
- Acoustics and Ultrasonics
- Biomedical Engineering
Background:
- Accurate measurement of wideband ultrasonic fields is crucial for advanced applications.
- Existing hydrophones often face limitations in sensitivity, size, or bandwidth.
- Fiber optic sensors offer potential for high sensitivity and miniaturization.
Purpose of the Study:
- To develop a highly sensitive and compact hydrophone for wideband ultrasonic field measurement.
- To investigate the performance of a pi-phase-shifted fiber Bragg grating for acoustic sensing.
- To assess the suitability of the developed hydrophone for medical imaging applications.
Main Methods:
- Fabrication of a pi-phase-shifted fiber Bragg grating exhibiting sharp, pressure-sensitive resonance.
- Monitoring the grating's resonance wavelength using a continuous-wave (CW) laser to detect pressure variations.
- Characterization of sensor performance, including effective size, pressure sensitivity, and bandwidth.
Main Results:
- The developed hydrophone achieved a high finesse resonance, enabling exceptional sensitivity.
- Effective sensor length was reduced to 270 μm due to light localization effects.
- Achieved pressure sensitivity of 440 Pa and an effective bandwidth of 10 MHz.
Conclusions:
- The pi-phase-shifted fiber Bragg grating hydrophone offers a novel approach to sensitive ultrasonic detection.
- The compact size, high sensitivity, and wide bandwidth make it suitable for demanding applications.
- The design shows significant promise for medical imaging modalities like optoacoustic tomography.
