Collection efficiency of optical photons generated from microwave excitations of a Bose-Einstein condensate

TL;DR

This paper investigates how a Bose-Einstein condensate can enhance the efficiency of converting microwave photons to optical photons via stimulated Raman scattering, optimizing collection into optical fibers.

Contribution

It analyzes the effects of phase-matching and bosonic enhancement on photon collection efficiency in microwave-to-optical transduction using BECs.

Findings

Optimal conditions for photon collection are identified.

Phase-matched direction yields superradiant scattering.

Off-phase-matched scattering allows photon separation from readout pulse.

Abstract

Stimulated Raman scattering of atoms with $\Lambda$-configuration of levels is a promising tool for transducing microwave photons to optical photons. We consider an atomic Bose-Einstein condensate whose large phase-space density highly amplifies the coupling to the microwave field. Due momentum transfer to the condensate, stimulated photon scattering can occur outside of the phase-matched direction, which can be used to separate the converted photons from the strong Raman readout pulse. Conversely, in the phase-matched direction, superradiant scattering due to bosonic enhancement leads to increased efficiency of the microwave to optical conversion. We determine the optimal conditions for the emitted optical photons to be collected into the guided modes of optical fibers.