Frequency-tunable biphoton generation via spontaneous four-wave mixing

TL;DR

This paper demonstrates how to tune biphoton frequencies in spontaneous four-wave mixing by using a detuned coupling field, revealing effects on pairing ratio and temporal profiles, with implications for quantum communication.

Contribution

It introduces a method to achieve frequency tunability in biphoton generation via SFWM using a detuned coupling field and analyzes its effects on efficiency and wavepacket profiles.

Findings

Detuned coupling field enables biphoton frequency tuning.

Increased coupling power mitigates efficiency loss.

Blue- and red-detuning produce distinct temporal wavepacket profiles.

Abstract

We present experimental results on tuning biphoton frequency by introducing a detuned coupling field in spontaneous four-wave mixing (SFWM), and examine its impact on the pairing ratio. This tunability is achieved by manipulating the inherent electromagnetically induced transparency (EIT) effect in the double-$\Lambda$ scheme. Introducing a detuned coupling field degrades the efficiency of EIT-based stimulated four-wave mixing, which in turn reduces the biphoton pairing ratio. However, this reduction can be mitigated by increasing the optical power of the coupling field. Additionally, we observe that blue- and red-detuning the biphoton frequency results in distinct temporal profiles of biphoton wavepackets due to phase mismatch. These findings provide insights into the mechanisms of frequency-tunable biphoton generation via SFWM, and suggest potential optimizations for applications in quantum communication and information processing.