FEMTOSECOND TRANSILLUMINATION TOMOGRAPHY IN THICK TISSUES

We describe diffuse-light time-gated imaging with transillumination op tical coherence tomography. Sub-millimeter-resolution imaging of objec ts hidden in thick biological tissue is achieved in caws in which ball istic light is absent by selecting only the early-arriving coherent po rtion of the diffuse transmitted light. By using a femtosecond laser a s a high-power low-coherence light source, we perform high-sensitivity (130-dB dynamic range) optical gating with interferometric heterodyne detection. The dependence of image resolution on coherent photon arri val time is investigated in model scattering media.