Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 Apr 23;22(9):3250.
doi: 10.3390/s22093250.

All Optical Speckle Contrast-Based Vibration Sensor for Photoacoustic Signal Detection

Matan Benyamin  1 , Zeev Zalevsky  1
Affiliations

All Optical Speckle Contrast-Based Vibration Sensor for Photoacoustic Signal Detection

Matan Benyamin et al. Sensors (Basel). .

Abstract

Remote detection of photoacoustic signals is a well desired ability, enabling to perform advanced imaging in scenarios where contact is not possible. Various unique solutions have been suggested, including a camera-based speckle contrast photoacoustic detection. In this manuscript, a significant upgrade to the camera-based speckle contrast approach is presented and experimentally demonstrated. This solution is based on all-optical vibration sensing setup. The technique is based on spectral estimation of speckle pattern contrast and relies on several pre-developed works. First, it relies on the suggested application of speckle contrast to vibration sensing, and then on the realization of intensity pattern spectral manipulation, using a shearing interferometer. The method is evaluated and compared to traditional contrast estimation, and demonstrated in several applications in various vibration frequency band such as photoacoustic signal analysis and phonocardiographic heart sounds. The method is also applicable to measuring contrast changes due to a general speckle changing behavior, rather than surface vibration alone.

Keywords: all-optical; non-contact vibration detection; photoacoustic; speckle contrast.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
The system. The PUMP is the photoacoustic excitation laser relevant only for the photoacoustic part of the manuscript. The detection system consists of all the components on the right side of the sample. A PROBE laser illuminates the vibrating object. The reflected speckle pattern is diffused by a rotating diffuser RF, moving forward to a shearing interferometer SI, containing a corner prism CP, a mirror M1, and a beam splitter BS1. Then, the generated spectrum passes through a phase plate PM which retards central low frequency by π and thus, creates subtraction of the low frequencies from the high frequencies. The two channels are focused onto the detector D.
Figure 2
Figure 2
(a) A set of simulated speckle pattern in different contrast affecting scenarios. Each image represents a degrading contrast of the speckle pattern, due to heavier smoothing. (b) A comparison between contrast drop of traditional statistical calculation, and the suggested optical spectral estimation, for the corresponding images from (a).
Figure 3
Figure 3
Contrast estimation method response to a non-uniform intensity distribution. (a) A set of speckle images similar to the ones presented in Figure 2, only this time not with uniform illumination, but a gaussian intensity distribution. (b) The corresponding contrast values for the set of patterns from both estimation methods.
Figure 4
Figure 4
Photoacoustic signal reconstruction-compared to piezo electric transducer.
Figure 5
Figure 5
Chest movement signal reconstruction.
Figure 6
Figure 6
Blood flow signal reconstruction.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

References

    1. Calasso I.G., Craig W., Diebold G.J. Photoacoustic Point Source. Phys. Rev. Lett. 2001;86:3550–3553. doi: 10.1103/PhysRevLett.86.3550. - DOI - PubMed
    1. Ntziachristos V., Yoo J.S., van Dam G.M. Current Concepts and Future Perspectives on Surgical Optical Imaging in Cancer. J. Biomed. Opt. 2010;15:066024. doi: 10.1117/1.3523364. - DOI - PubMed
    1. Zhang H.F., Puliafito C.A., Jiao S. Photoacoustic Ophthalmoscopy for In Vivo Retinal Imaging: Current Status and Prospects. Ophthalmic Surg. Lasers Imaging. 2011;42:S106–S115. doi: 10.3928/15428877-20110627-10. - DOI - PMC - PubMed
    1. Paltauf G., Nuster R., Haltmeier M., Burgholzer P. Photoacoustic Tomography Using a Mach-Zehnder Interferometer as an Acoustic Line Detector. Appl. Opt. 2007;46:3352–3358. doi: 10.1364/AO.46.003352. - DOI - PubMed
    1. Layton M.R., Bucaro J.A. Optical Fiber Acoustic Sensor Utilizing Mode-Mode Interference. Appl. Opt. 1979;18:666–670. doi: 10.1364/AO.18.000666. - DOI - PubMed

LinkOut - more resources