Translator Disclaimer
Paper
23 February 2009 Effect of time gating and polarization discrimination of propagating light in turbid media during angular domain imaging (ADI)
Author Affiliations +
Abstract
Angular Domain Imaging (ADI) employs an angular filter array to accept photons within a small acceptance angle along the axis of an aligned laser light source and preferentially reject scattered light. Simulations show that the accepted photons travel the shortest paths between source and detector and are therefore the earliest to arrive. We fabricated angular filter arrays using silicon bulk micromachining and found that an array of 60 μm square shape microtunnels 1 cm in length accepted photons within 0.48 degree of axis of the micro-tunnels. This small acceptance angle rejected most of the scattered light and sub-millimeter resolution targets could be resolved in a few centimeters of turbid medium with at least six times reduced mean free path. ADI through media with higher scattering coefficients was not achievable due to unwanted acceptance of late arriving scattered photons. To reject the late arriving photons, we added time-domain filtration and linear polarization to ADI. The implementation of a time-gated camera, a 780 nm femtosecond pulsed laser, and linear polarization to our ADI system resulted in improved image contrast. The use of ADI with time-gating (gate width 250 ps) and linear polarization enabled visualization of sub-millimeter absorbing objects with approximately eight times higher image contrast compared to ADI in a scattering medium equivalent to six times reduced mean free path.
© (2009) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Fartash Vasefi, Eldon Ng, Bozena Kaminska, Glenn H. Chapman, and Jeffrey J. L. Carson "Effect of time gating and polarization discrimination of propagating light in turbid media during angular domain imaging (ADI)", Proc. SPIE 7182, Imaging, Manipulation, and Analysis of Biomolecules, Cells, and Tissues VII, 718217 (23 February 2009); https://doi.org/10.1117/12.809439
PROCEEDINGS
10 PAGES


SHARE
Advertisement
Advertisement
RELATED CONTENT

Photon type selection in contrasted scattering media
Proceedings of SPIE (February 02 2001)
Tissue optics: tomography and topography
Proceedings of SPIE (March 04 1999)
Use of a radial angular filter array to estimate the...
Proceedings of SPIE (February 13 2012)
Angular domain fluorescent lifetime imaging in turbid media
Proceedings of SPIE (February 25 2009)
Tumor detection using time-resolved light transillumination
Proceedings of SPIE (November 01 1991)

Back to Top