Prof. Ady Arie
School of Electrical Engineering, Tel Aviv University, Tel Aviv, Israel
A nonlinear hologram can record the amplitude and phase of a desired optical waveform by spatially modulating the second order nonlinear coefficient. When the hologram is illuminated by a pump beam, this waveform is reconstructed at the second harmonic frequency. Here we extend the application of nonlinear holography to the quantum optical regime. Specifically, we concentrate on the process of spontaneous parametric down conversion (SPDC), where the pump photon spontaneously splits inside the nonlinear crystal to signal and idler photons. An interesting new possibility is to design nonlinear holograms that will shape the first and second order correlations of the down-converted signal and idler photons in either the spatial or the spectral domain. These domains span a multi-dimensional Hilbert space, thus providing a large alphabet for encoding information on a single photon, with important applications in quantum key distribution and quantum computing. Specifically, I will present recent results of the direct generation of spatial qubits and qudits, and on the spectral shaping of bright squeezed vacuum sources.