Measurement of Ultra-Short Single-Photon Pulse Duration with Two-Photon Interference

We proposed a protocol of measuring the duration of ultra-short single-photon pulse with two-photon interference. The pulse duration can be obtained from the width of the visibility of two-photon Hong-Ou-Mandel interference or the indistinguishability of the two photons. Moreover, the shape of a single-photon pulse can be measured with ultra-short single-photon pulses through the two-photon interference.