Improvement in fluorescence confocal microscopy for obtaining better depth perception

We propose a technique for improving the image quality in fluorescence confocal microscopy imaging by exploiting the phase difference of the fluorescence emission from different depths of the sample. The technique uses a modulated excitation beam and homodyne detection scheme. The image after homodyne detection consists of an unmodulated term and a sinusoidally modulated term. The unmodulated term does not have any phase dependence. The modulated term has a phase dependence on the depth of the sample from which emission is occurring. In the proposed methodology, the unmodulated term is removed giving rise to images with better depth perception.