Klyshko's Advanced-Wave Picture in Stimulated Parametric Down-Conversion with a Spatially Structured Pump Beam

TL;DR

This paper extends the advanced-wave picture to structured pump beams and stimulated emission in parametric down-conversion, providing a new experimental approach for designing and testing quantum optics experiments.

Contribution

It introduces the advanced-wave picture for structured pump beams and demonstrates its use in designing and testing experiments with stimulated parametric down-conversion.

Findings

Experimental validation of advanced-wave design strategy

Effective in predicting stimulated emission outcomes

Applicable to structured pump beam configurations

Abstract

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, 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.