Comparison of in-vivo measured optical path length distribution of backscattered light in human skin and time-resolved Monte Carlo simulations

2021 ◽  
Author(s):  
Miran Burmen ◽  
Peter Naglic ◽  
Janis Spigulis
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Human Skin ◽  
Path Length ◽  
Length Distribution ◽  
Optical Path Length ◽  
Optical Path ◽  
Time Resolved

scholarly journals In vivo optical imaging of physiological responses to photostimulation in human photoreceptors

2016 ◽  
Vol 113 (46) ◽  
pp. 13138-13143 ◽  
Author(s):  
Dierck Hillmann ◽  
Hendrik Spahr ◽  
Clara Pfäffle ◽  
Helge Sudkamp ◽  
Gesa Franke ◽  
...  
Keyword(s):  
Path Length ◽  
Ex Vivo ◽  
Optical Path Length ◽  
Optical Path ◽  
Clinical Diagnostics ◽  
Photoreceptor Outer Segment ◽  
Cellular Processes ◽  
Tomography System ◽  
Length Changes

Noninvasive functional imaging of molecular and cellular processes of vision may have immense impact on research and clinical diagnostics. Although suitable intrinsic optical signals (IOSs) have been observed ex vivo and in immobilized animals in vivo, detecting IOSs of photoreceptor activity in living humans was cumbersome and time consuming. Here, we observed clear spatially and temporally resolved changes in the optical path length of the photoreceptor outer segment as a response to an optical stimulus in the living human eye. To witness these changes, we evaluated phase data obtained with a parallelized and computationally aberration-corrected optical coherence tomography system. The noninvasive detection of optical path length changes shows neuronal photoreceptor activity of single cones in living human retina, and therefore, it may provide diagnostic options in ophthalmology and neurology and could provide insights into visual phototransduction in humans.

scholarly journals DIC image reconstruction using an energy minimization framework to visualize optical path length distribution

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Krisztian Koos ◽  
József Molnár ◽  
Lóránd Kelemen ◽  
Gábor Tamás ◽  
Peter Horvath
Keyword(s):  
Image Reconstruction ◽  
Energy Minimization ◽  
Path Length ◽  
Length Distribution ◽  
Optical Path Length ◽  
Optical Path

Experimental validation of Monte Carlo and finite-element methods for the estimation of the optical path length in inhomogeneous tissue

1996 ◽  
Vol 35 (19) ◽  
pp. 3362 ◽  
Author(s):  
Eiji Okada ◽  
Martin Schweiger ◽  
Simon R. Arridge ◽  
Michael Firbank ◽  
David T. Delpy
Keyword(s):  
Finite Element ◽  
Monte Carlo ◽  
Finite Element Methods ◽  
Path Length ◽  
Experimental Validation ◽  
Optical Path Length ◽  
Optical Path

Investigation of particulate systems using optical pathlength spectroscopy

2000 ◽  
Vol 627 ◽  
Author(s):  
Gabriel Popescu ◽  
Aristide Dogariu
Keyword(s):  
Path Length ◽  
Random Media ◽  
Michelson Interferometer ◽  
Industrial Process ◽  
Optical Path Length ◽  
Industrial Applications ◽  
Optical Path ◽  
Interference Signal ◽  
Optical Length ◽  
Reference Mirror

ABSTRACTIn many industrial applications involving granular media, knowledge about the structural transformations suffered during the industrial process is desirable. Optical techniques are noninvasive, fast, and versatile tools for monitoring such transformations. We have recently introduced optical path-length spectroscopy as a new technique for random media investigation. The principle of the method is to use a partially coherent source in a Michelson interferometer, where the fields from a reference mirror and the sample are combined to obtain an interference signal. When the system under investigation is a multiple-scattering medium, by tuning the optical length of the reference arm, the optical path-length probability density of light backscattered from the sample is obtained. This distribution carries information about the structural details of the medium. In the present paper, we apply the technique of optical path-length spectroscopy to investigate inhomogeneous distributions of particulate dielectrics such as ceramics and powders. The experiments are performed on suspensions of systems with different solid loads, as well as on powders and suspensions of particles with different sizes. We show that the methodology is highly sensitive to changes in volume concentration and particle size and, therefore, it can be successfully used for real-time monitoring. In addition, the technique is fiber optic-based and has all the advantages associated with the inherent versatility.

scholarly journals Stray light characterization with ultrafast time-of-flight imaging

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
L. Clermont ◽  
W. Uhring ◽  
M. Georges
Keyword(s):  
Path Length ◽  
Imaging System ◽  
Time Of Flight ◽  
Optical Path Length ◽  
Optical Path ◽  
Stray Light ◽  
Laser Source ◽  
Space Telescopes ◽  
Characterization Methods ◽  
Instance Space

AbstractUnderstanding stray light (SL) is a crucial aspect in the development of high-end optical instruments, for instance space telescopes. As it drives image quality, SL must be controlled by design and characterized experimentally. However, conventional SL characterization methods are limited as they do not provide information on its origins. The problem is complex due to the diversity of light interaction processes with surfaces, creating various SL contributors. Therefore, when SL level is higher than expected, it can be difficult to determine how to improve the system. We demonstrate a new approach, ultrafast time-of-flight SL characterization, where a pulsed laser source and a streak camera are used to record individually SL contributors which travel with a specific optical path length. Furthermore, the optical path length offers a means of identification to determine its origin. We demonstrate this method in an imaging system, measuring and identifying individual ghosts and scattering components. We then show how it can be used to reverse-engineer the instrument SL origins.

Sign in / Sign up

Export Citation Format

Share Document