Shaping the illumination beams for STED imaging through highly scattering media

Imaging through scattering media finds applications in diverse fields from biomedicine to autonomous driving. However, interpreting the resulting images is difficult due to blur caused by the scattering of photons within the medium. Transient information, captured with fast temporal sensors, can be used to significantly improve the quality of images acquired in scattering conditions. Photon scattering, within a highly scattering media, is well modeled by the diffusion approximation of the Radiative Transport Equation (RTE). Its solution is easily derived which can be interpreted as a Spatio-Temporal Point Spread Function (STPSF). In this paper, we first discuss the properties of the ST-PSF and subsequently use this knowledge to simulate transient imaging through highly scattering media. We then propose a framework to invert the forward model, which assumes Poisson noise, to recover a noise-free, unblurred image by solving an optimization problem.

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Numerical simulation of spatio-temporal coupling effect in femtosecond laser pulse propagated through multi-layer scattering media

2020 International Conference Laser Optics (ICLO) ◽

10.1109/iclo48556.2020.9285698 ◽

2020 ◽

Author(s):

A.V. Belashov ◽

N.V. Petrov

Keyword(s):

Numerical Simulation ◽

Laser Pulse ◽

Femtosecond Laser ◽

Femtosecond Laser Pulse ◽

Coupling Effect ◽

Scattering Media ◽

Temporal Coupling ◽

Spatio Temporal

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Linear Reconstruction Techniques Applied to Scattering Media

2020 5th International Conference on Biomedical Imaging, Signal Processing ◽

10.1145/3436349.3436350 ◽

2020 ◽

Author(s):

Benjamin T Cecchetto ◽

James Stewart

Keyword(s):

Scattering Media ◽

Linear Reconstruction

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OAM light propagation through tissue

Scientific Reports ◽

10.1038/s41598-021-82033-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Netanel Biton ◽

Judy Kupferman ◽

Shlomi Arnon

Keyword(s):

Light Propagation ◽

Biological Imaging ◽

Gaussian Beams ◽

Medical Implants ◽

Optical Wireless ◽

Scattering Media ◽

Valuable Contribution ◽

Light Beams ◽

First Time ◽

Diffuse Media

AbstractA major challenge in use of the optical spectrum for communication and imaging applications is the scattering of light as it passes through diffuse media. Recent studies indicate that light beams with orbital angular momentum (OAM) can penetrate deeper through diffuse media than simple Gaussian beams. To the best knowledge of the authors, in this paper we describe for the first time an experiment examining transmission of OAM beams through biological tissue with thickness of up to a few centimeters, and for OAM modes reaching up to 20. Our results indicate that OAM beams do indeed show a higher transmittance relative to Gaussian beams, and that the greater the OAM, the higher the transmittance also up to 20, Our results extend measured results to highly multi scattering media and indicate that at 2.6 cm tissue thickness for OAM of order 20, we measure nearly 30% more power in comparison to a Gaussian beam. In addition, we develop a mathematical model describing the improved permeability. This work shows that OAM beams can be a valuable contribution to optical wireless communication (OWC) for medical implants, optical biological imaging, as well as recent innovative applications of medical diagnosis.

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