Abstract

Consider an experiment where a single photon is split into two wave-packets by a beam splitter and where the two wave packets are made to overlap in a specific region in space If the two wave-packets arrive at the same time, an interference pattern can be recorded by a classical detector such as a photographic plate If however, the difference in arrival time between the two wave-packets is made to be larger than the coherence time of the wave packets, the interference pattern, as recorded by the detector, will disappear It has been argued that if the classical detector is replaced by a material that can remember the phase of the electromagnetic field, i e a material with a long homogeneous dephasing time, it would be possible to record the interference between the two wave-packets even if the time difference between them is much larger than the coherence time [1] We denote this singlephoton self-interference The interference pattern would take the form of a frequency dependent population grating in the material and could be detected by diffracting a light pulse on this grating

© 2000 IEEE