Optimal optical filter for a short pulse with a bandwidth-limited receiver

For an optical short pulse with white background noise, an optical filter preceding the photodetector can reduce the noise. The optimal optical filter is derived to balance the amount of the output noise with the energy of the output signal. As a numerical example, for a Gaussian optical pulse with a Gaussian receiver filter, the optimal optical filter is also a Gaussian filter with a bandwidth between that of the optical pulse and the receiver filter. (C) 2009 Optical Society of America