Compact sub-kilohertz low-frequency quantum light source based on four-wave mixing in cesium vapor
Related Experiment Video
Updated: Feb 13, 2026

Gradient Echo Quantum Memory in Warm Atomic Vapor
Published on: November 11, 2013
Abstract:
Using a nondegenerate four-wave mixing (FWM) process based on a double-Λ scheme in hot cesium vapor, we demonstrate a compact diode-laser-pumped quantum light source for the generation of quantum correlated twin beams with a maximum squeezing of 6.5 dB. The squeezing is observed at a Fourier frequency in the audio band down to 0.7 kHz which, to the best of our knowledge, is the first observation of sub-kilohertz intensity-difference squeezing in an atomic system so far. A phase-matching condition is also investigated in our system, which confirms the spatial-multi-mode characteristics of the FWM process. Our compact low-frequency squeezed light source may find applications in quantum imaging, quantum metrology, and the transfer of optical squeezing onto a matter wave.
Related Concept Videos
The Wave Nature of Light
Quantum Numbers
The Quantum-Mechanical Model of an Atom
Vapor Pressure
Vaporization
Vapor Pressure Lowering

