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Efficient injection of light into strongly scattering medium is the foremost condition for a wide range of sensing and imaging applications. However, turbidity leads to strong suppression of light intensity at distances greater than transport mean free path away from the source.
Tailoring the incident fields via wavefront shaping technique offers an exciting approach to enhance light injection by exploiting the so-called open eigenchannels that penetrate to depths much greater than transport mean free path. The drawback of this approach is that it requires a feedback either from within or at the opposite side of the sample. Tailoring incident wavefront based either on optimization or characterization of transmission matrix of the medium is an imperfect and a time-consuming process that limits efficacy and range of applications of this approach.
Recently, a much simpler strategy for enhanced light injection was proposed and experimentally demonstrated. It is based on exploiting pore imperfections in the surface of turbid medium that can readily exist in many natural and artificial materials. This technique turned out to be highly efficient in enhancing light-matter interactions, because upon injection, the light is unlikely to escape through the same pore.
In this talk, we will introduce the physical mechanisms for the enhanced injection in different regimes of system parameters such as the size of the pore, transport mean free path, and absorption length. We will also discuss a possibility of combining this microstructure-based approach with wavefront shaping.
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