Estimating the depth and lifetime of a fluorescent inclusion in a turbid medium using a simple time-domain optical method

A simple time-domain optical method for estimating the depth (d) and lifetime (tau) of fluorescent inclusions in a turbid medium is described. We demonstrate the method for depth and lifetime estimation of a fluorescent inclusion directly by fitting a monoexponential decay (tau(eff)) of the temporal position of the temporal point-spread function and the measurement of its maximum temporal position (t(max)). Since both of these measurements are intensity independent, this method provides a robust and efficient approach. This method is validated with experimental data.