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Quantitative image contrast enhancement in time-gated transillumination of scattering media

Sedarsky, David LU ; Berrocal, Edouard LU and Linne, Mark (2011) In Optics Express 19(3). p.1866-1883
Abstract
Experimental work in turbid media has shown that transillumination images can be significantly improved by limiting light collection to a subset of photons which are minimally distorted by scattering. The literature details numerous schemes (commonly termed ballistic imaging), most often based on time-gating and/or spatially filtering the detected light. However, due to the complex nature of the detected signal, analysis of this optical filtering process has been heretofore limited to qualitative comparisons of image results. In this article we present the implementation of a complete system model for the simulation of light propagation, including both the scattering medium and all stages of the optical train. Validation data from... (More)
Experimental work in turbid media has shown that transillumination images can be significantly improved by limiting light collection to a subset of photons which are minimally distorted by scattering. The literature details numerous schemes (commonly termed ballistic imaging), most often based on time-gating and/or spatially filtering the detected light. However, due to the complex nature of the detected signal, analysis of this optical filtering process has been heretofore limited to qualitative comparisons of image results. In this article we present the implementation of a complete system model for the simulation of light propagation, including both the scattering medium and all stages of the optical train. Validation data from ballistic imaging (BI) measurements of monodisperse scatterers with diameter, d = 0.7 mu m, at optical depths 5, 10, and 14, are compared with model results, showing excellent agreement. In addition, the validated model is subsequently applied to a modified time-gated optical system to probe the comparative performance of the BI system used in validation and the modified BI system. This instrument comparison examines scatterers with diameters of 0.7 and 15 mu m at optical depths 10 and 14, and highlights the benefits of each system design for these specific scattering conditions. These results show that the modified optics configuration is more suitable for particles which are much larger than the incident wavelength, d >> lambda, while the configuration employed in the validation system provides a better contrast for particle diameters on the order of the wavelength, d similar to lambda, where the scattering process exhibits a more homogeneous phase function. The insights and predictions made available by the full numerical model are important for the design of optimized imaging systems suited to specific turbid media, and make possible the quantitative understanding of both the effects of light propagation in the measurement and the performance of the complete imaging system. (C) 2011 Optical Society of America (Less)
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author
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organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Optics Express
volume
19
issue
3
pages
1866 - 1883
publisher
Optical Society of America
external identifiers
  • wos:000286807100022
  • scopus:79851492331
ISSN
1094-4087
DOI
10.1364/OE.19.001866
language
English
LU publication?
yes
id
df5f1102-0c40-488d-aa9a-b3a10bc2de55 (old id 1868286)
date added to LUP
2016-04-01 12:57:34
date last changed
2022-02-26 18:33:18
@article{df5f1102-0c40-488d-aa9a-b3a10bc2de55,
  abstract     = {{Experimental work in turbid media has shown that transillumination images can be significantly improved by limiting light collection to a subset of photons which are minimally distorted by scattering. The literature details numerous schemes (commonly termed ballistic imaging), most often based on time-gating and/or spatially filtering the detected light. However, due to the complex nature of the detected signal, analysis of this optical filtering process has been heretofore limited to qualitative comparisons of image results. In this article we present the implementation of a complete system model for the simulation of light propagation, including both the scattering medium and all stages of the optical train. Validation data from ballistic imaging (BI) measurements of monodisperse scatterers with diameter, d = 0.7 mu m, at optical depths 5, 10, and 14, are compared with model results, showing excellent agreement. In addition, the validated model is subsequently applied to a modified time-gated optical system to probe the comparative performance of the BI system used in validation and the modified BI system. This instrument comparison examines scatterers with diameters of 0.7 and 15 mu m at optical depths 10 and 14, and highlights the benefits of each system design for these specific scattering conditions. These results show that the modified optics configuration is more suitable for particles which are much larger than the incident wavelength, d >> lambda, while the configuration employed in the validation system provides a better contrast for particle diameters on the order of the wavelength, d similar to lambda, where the scattering process exhibits a more homogeneous phase function. The insights and predictions made available by the full numerical model are important for the design of optimized imaging systems suited to specific turbid media, and make possible the quantitative understanding of both the effects of light propagation in the measurement and the performance of the complete imaging system. (C) 2011 Optical Society of America}},
  author       = {{Sedarsky, David and Berrocal, Edouard and Linne, Mark}},
  issn         = {{1094-4087}},
  language     = {{eng}},
  number       = {{3}},
  pages        = {{1866--1883}},
  publisher    = {{Optical Society of America}},
  series       = {{Optics Express}},
  title        = {{Quantitative image contrast enhancement in time-gated transillumination of scattering media}},
  url          = {{https://lup.lub.lu.se/search/files/85589927/oe_19_3_1866.pdf}},
  doi          = {{10.1364/OE.19.001866}},
  volume       = {{19}},
  year         = {{2011}},
}