Ultra Compact low cost two mode squeezed light source

TL;DR

This paper presents a compact, low-cost, and efficient two-mode squeezed light source at 795 nm using four-wave mixing in hot rubidium vapor, suitable for quantum sensing and networking applications.

Contribution

The authors develop a portable, narrowband squeezed-light source with low pump power requirements and high squeezing performance, advancing practical quantum technology deployment.

Findings

Achieves up to -8 dB of intensity-difference squeezing

Operates at low pump power of 300 mW

Features a compact, modular design suitable for quantum applications

Abstract

Quantum-correlated states of light, such as squeezed states, constitute a fundamental resource for quantum technologies, enabling enhanced performance in quantum metrology, quantum information processing, and quantum communications. The practical deployment of such technologies requires squeezed-light sources that are compact, efficient, low-cost, and robust. Here we report a compact narrowband source of two-mode squeezed light at 795 nm based on four-wave mixing in hot 85Rb atomic vapor. The source is implemented in a small, modular architecture featuring a single fiber-coupled input, an electro-optic phase modulator combined with a single Fabry-Perot etalon for probe generation, and two free-space output modes corresponding to the signal and conjugate fields. Optimized for low pump power, the system achieves up to -8 dB of intensity-difference squeezing at an analysis frequency of 0.8 MHz with a pump power of only 300 mW. The intrinsic narrowband character of the generated quantum states makes this source particularly well suited for atomic-based quantum sensing and quantum networking, including interfaces with atomic quantum memories. Our results establish a versatile and portable platform for low-SWaP squeezed-light generation, paving the way toward deployable quantum-enhanced technologies.