On the Advanced Wave Model of Parametric Down-Conversion

Chih‐Sung Chuu, Chun-Yao Yang, Jim Jr-Min Lin +3 more

Filippus S. Roux

Alexander I. Lvovsky, Thomas Aichele

We discuss a classical model allowing one to visualize and characterize the optical mode of the single photon generated by means of a conditional measurement on a biphoton produced in parametric down-conversion. The model is based on Klyshko's advanced wave interpretation, but extends beyond it, providing a precise mathematical description of the advanced wave. The optical mode of the conditional photon is shown to be identical to the mode of the classical difference-frequency field generated due to nonlinear interaction of the partially coherent advanced wave with the pump pulse. With this "nonlinear advanced wave model" most coherence properties of the conditional photon become manifest, which permits one to intuitively understand many recent results, in particular, in quantum imaging.

Dmitri S. Mogilevtsev

M. F. Z. Arruda, Willamys C. Soares, Stephen Patrick Walborn +4 more

The advanced-wave picture is ``... an intuitive treatment of two-photon correlation with the help of the concept of an effective field acting upon one of the two detectors and formed by parametric conversion of the advanced wave emitted by the second detector ...'' [A. V. Belinskii and D. N. Klyshko, Sov. Phys. JETP 78, 259 (1994)]. This quote from Belinskii and Klyshko nicely describes the concept of the advanced-wave picture: an intuitive tool for designing and predicting results from coincidence-based two-photon experiments. Up to now, the advanced-wave picture has been considered primarily for the case of an ideal plane-wave pump beam and only for design purposes. Here we study the advanced-wave picture for a structured pump beam and in the context of stimulated emission provoked by an auxiliary input laser beam. This suggests stimulated parametric down-conversion as a useful experimental tool for testing the experimental sets designed with the advanced-wave picture. We present experimental results demonstrating the strategy of designing the experiment with advanced-wave picture and testing with stimulated emission.

Luca Fasolo, L. Oberto, Luca Callegaro +1 more

The paper investigates the interplay of nonlinear effects with the non-ideal transmission properties of a Josephson Travelling Wave Parametric Amplifier (JTWPA). Experimental characterization using a microwave and DC cryogenic setup reveals periodic transmission modulation linked to the tuning of the Josephson inductances embedded in the line. The effects of impedance matching and resonant parametric down-conversion (PDC) are observed on a broadband scale, and the impact of design parameters and fabrication issues on device performance is analyzed. These findings contribute to the optimizing techniques for JTWPA devices, advancing quantum-limited amplifiers.