Open AccessInfluence of photo-detector's dead-time on the speckle contrast for blood flow measurement
Author(s) -
N. Cruz-Ojeda,
Rosario Porras-Aguilar,
R. Ramos-Garcı́a,
J. C. Ramírez-San-Juan
Publication year - 2015
Publication title -
journal of applied research and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.364
H-Index - 30
ISSN - 1665-6423
DOI - 10.1016/j.jart.2015.10.008
Subject(s) - speckle pattern , detector , dead time , contrast (vision) , optics , physics , intensity (physics) , statistics , mathematics
The statistics of temporal integration of dynamically scattered light is commonly employed to calculate the correlation time of the light and related physical properties of the object that produce it, i.e. scatterer's speed. Recently, studying the statistics of time-averaged fluorescence intensity, it was reported that a small dead-time (1% of the exposure time) of the photo-detector increases the correlation time by one order of magnitude compared with an ideal photo-detector. Applying the same theory to the speckle contrast calculation for blood flow measurement, we found that the effect of dead-time is negligible compared to an ideal photo-detector for contrast calculation