Reconstructing the full modal structure of photonic states by stimulated emission tomography

TL;DR

This paper provides a comprehensive theoretical framework for stimulated emission tomography (SET), enabling full reconstruction of the modal structure of biphoton states, including phase information, across various quadratic coupling regimes.

Contribution

It extends SET theory to include phase retrieval and applies to any quadratic coupling regime, enhancing modal characterization of biphotons.

Findings

Theoretical description of SET applicable to all quadratic coupling regimes.

Method to retrieve both modulus and phase of modal functions.

Discussion of measurement resolution limitations.

Abstract

Stimulated emission tomography is a powerful and successful technique to both improve the resolution and experimentally simplify the task of determining the modal properties of biphotons. In the present manuscript we provide a theoretical description of SET valid for any quadratic coupling regime between a non-linear medium and pump fields generating photons by pairs. We use our results to obtain not only information about the associated modal function modulus but also its phase, for any mode, and we discuss the specific case of time-frequency variables as well as the quantities and limitations involved in the measurement resolution.