Single-photon-level fractional Fourier imaging in the time-frequency domain

Our paper on ultrafast electro-optic time-frequency fractional Fourier imaging at the single-photon level is out in Optics Express 32, 9573.

The fractional Fourier transform is a rotation in time–frequency phase space. We implement it with electro-optic time lenses, which avoid the noise of nonlinear-optical approaches, so it works down to single photons.