title: Tandem pulsed acousto-optics: obtaining the tagged light fraction from modulated non-ideal speckle patterns.
abstract: Recently we presented novel methods for acousto-optic (AO) imaging of biological tissues, taking (1) the mean square difference of speckle patterns (subtraction method) or (2) the contrast of the summation of speckle patterns (summation method) acquired from nanosecond pulses of coherent light, fired at different ultrasound phases. In this study we relate the two methods both analytically and experimentally. We experimentally show that these two methods are nearly identical provided that the maximum achievable speckle contrast is determined correctly. We show with simulations that after correction the outcome is independent of experimental detection parameters. This makes the AO methods in this study reliable, allowing quantifying speckle observations in terms of the ultrasonically tagged fractions of light. The use of tandem nanosecond pulses in one burst of ultrasound overcomes the challenge of tissue dynamics.
authors.affiliation: Biomedical Photonic Imaging group, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, PO Box 217, 7500 AE Enschede, The Netherlands.
authors.forename: S G
authors.initials: SG
authors.lastname: Resink
authors.forename: W
authors.initials: W
authors.lastname: Steenbergen
mesh_terms: D000465:Algorithms; D016477:Artifacts; D064847:Multimodal Imaging / Q000379:methods* / Q000592:standards; D061848:Optical Imaging / Q000379:methods* / Q000592:standards; D014463:Ultrasonography / Q000379:methods* / Q000592:standards