Bypassing the filtering challenges in microwave-optical quantum transduction through optomechanical four-wave mixing

TL;DR

This paper proposes a novel microwave-optical quantum transduction method using four-wave mixing, which overcomes filtering challenges by producing widely separated photons, potentially improving efficiency over traditional techniques.

Contribution

It introduces a four-wave mixing approach for quantum transduction that avoids narrowband filtering issues, using higher-order optomechanical effects to enhance efficiency.

Findings

Four-wave mixing enables transduction with less stringent filtering requirements.

The proposed method can surpass conventional optomechanical coupling efficiencies.

Higher-order optomechanical effects are key to the new transduction process.

Abstract

Microwave-optical quantum transduction is a key enabling technology in quantum networking, but has been plagued by a formidable technical challenge. As most microwave-optical-transduction techniques rely on three-wave mixing processes, the processes consume photons from a driving telecom-band (pump) laser to convert input microwave photons into telecom-band photons detuned from the laser by this microwave frequency. However, cleanly separating out single photons detuned only a few GHz away from a classically bright laser in the same spatial mode requires frequency filters of unprecedented extinction over a very narrow transition band, straining the capabilities of today's technology. Instead of confronting this challenge directly, we show how one may achieve the same transduction objective with comparable efficiency using a four-wave mixing process in which $pairs$ of pump photons are consumed to produce transduced optical photons widely separated in frequency from the pump. We develop this process by considering higher-order analogues of photoelasticity and electrostriction than those used in conventional optomechanics, and examine how the efficiency of this process can be made to exceed conventional optomechanical couplings.