Frequency-to-Time Mapping Technique for Direct Spectral Characterization of Biphoton States From Pulsed Spontaneous Parametric Processes

The well-established frequency-to-time mapping technique is employed as a convenient and time-efficient method to directly characterize the spectral correlations of biphoton states from a pulsed-excited spontaneous parametric down-conversion process. We were enabled by this technique to implement for the first time, the spectral Hanbury-Brown and Twiss measurement, revealing directly the single frequency-mode bandwidth of the biphoton state.