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Updated: Jun 19, 2026
Integrated Photoacoustic Ophthalmoscopy and Spectral-domain Optical Coherence Tomography
Published on: January 15, 2013
On the speckle-free nature of photoacoustic tomography
Zijian Guo1, Li Li, Lihong V Wang
1Department of Biomedical Engineering, Optical Imaging Laboratory, Washington University, 1 Brookings Drive, Saint Louis, Missouri 63130, USA.
Purpose:
A long-standing conundrum is why photoacoustic tomography (PAT) possesses the unique ability to produce images devoid of speckle artifacts while all other coherent imaging technologies do not.
Methods:
In this paper, we explain the inherent mechanism that suppresses speckle in PAT, and the analysis was validated by simulations based on an experimental PAT system.
Results:
We found that the speckle-free feature of PAT results directly from the optical absorption contrast.
Conclusions:
All optical absorbers expand on laser excitation, and therefore all initial photoacoustic pressure rises are positive, which engenders strong correlations among the photoacoustic waves from the absorbers. As a result, prominent boundaries always build up in photoacoustic images and suppress the interior speckle.
