WAVEFRONT SHAPING FOR IMPROVED IMAGING CONTRAST IN OPTICAL COHERENCE TOMOGRAPHY

这个子项目是利用这些资源的众多研究子项目之一

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Tissue is a heterogeneous, turbid medium, which causes multiple scattering of a light propagating through it; thus the light becomes diffused over transmission distances of a few mean-free paths. In visible and near infrared regime, one mean-free path is on the order of 100 ¿m. Thus, the depth at which an incident wavefront can be effectively focused within a tissue sample is limited. Multiple scattering of light therefore reduces the contrast and hence the imaging depth such as in case of confocal microscopy, multiphoton microscopy, and optical coherence tomography. In addition, light diffusion due to multiple scattering also limits the depth range and effectiveness of light-based therapeutic modalities such as photodynamic therapy. However, elastic-scattering effects are deterministic and reversible. The goal of this study is to develop efficient ways to appropriately shape the illumination wavefield so that the light both penetrates deep within the sample and is concentrated at a region of interest in order to improve current imaging and therapeutic modalities.