Automatic dispersion cancellation is one of the hallmark features of quantum interference, but does it really need any quantum resources? In this paper we demonstrate a new interference technique, called chirped-pulse interferometry, which exhibits automatic dispersion cancellation without entanglement or any quantum effects. No longer constrained to running two photons at a time, the signal is orders of magnitude larger than what can be obtained with entanglement. The technique relies on oppositely chirped laser pulses which have classical, as opposed to quantum, frequency correlations.
The cover image below shows the spectrum of the sum-frequency generation output of the interferometer as a function of delay. The break in the centre (near the red part) is the CPI interference dip and shares many important features with its quantum analogue the Hong-Ou-Mandel dip. For more information see the article here or on the ArXiv.
