Generation of bright broadband-squeezed light and broadband quantum interferometry

Carlton M. Caves

Jun Liu, Yan Liu, Xiaowei Wu +1 more

ABSTRACT Broadband bright squeezed states are important quantum resources that play a crucial role in quantum information and quantum measurement. Here, we present the broadband bright pulsed squeezed states generated by a single‐pass optical parametric amplification based on a custom‐poled potassium titanyl phosphate crystal. By optimizing the spatial mode of the picosecond pump beams, a bright squeezed light with 1.7 dB squeezing and output power of 5 mW is obtained. With a spatial light modulator, the spatial distribution of the bright squeezed light is shaped into perfect vortex beams with topological charges up to , while the squeezing level is 1.4 dB. The presented squeezed states provide essential resources for advanced quantum optics applications. Graphical Abstract

Ruixin Li, Bingnan An, Nanjing Jiao +4 more

The dominant technical noise of a free-running laser practically limits bright squeezed light generation, particularly within the MHz band. To overcome this, we develop a comprehensive theoretical model for nonclassical power stabilization, and propose a novel bright squeezed light generation scheme incorporating hybrid power noise suppression. Our approach integrates broadband passive power stabilization with nonclassical active stabilization, extending the feedback bandwidth to MHz frequencies. This hybrid technique achieves an additional 9 dB technical noise suppression, establishing critical prerequisites for broadband bright squeezed light generation. Finally, a -5.5 dB bright squeezed light at 1 mW with kHz-MHz squeezing bandwidth was generated. The experimental results show excellent agreement with theoretical predictions, which represent we have comprehensively demonstrated a milliwatt-order bright squeezed light across kHz-MHz frequencies. Our work enables new quantum metrology applications and paves the way for next-generation quantum-enhanced technologies. Nonclassical hybrid passive-active power stabilization enables milliwatt-level bright squeezing across kHz-MHz band.

Z. Ficek, R. Tanaś

Juan F. Hodelin

Sahil Pontula, Jamison Sloan, Nicholas Rivera +1 more

Abstract The generation and application of squeezed light have long been central goals of quantum optics. Intensity noise squeezing of bright (coherent) states (“bright squeezing”), in contrast to squeezed vacuum, is relatively underdeveloped. The current state of the art has generally been restricted to narrow operating wavelength ranges and does not natively support strong intracavity and broadband output squeezing. Here, we show how lasers with sharp intensity‐dependent dissipation can support strong intensity noise squeezing from infrared (IR) to terahertz (THz) wavelengths, the latter of which has eluded quantum light generation. Our protocol realizes strongly ( dB) intensity noise‐squeezed intracavity quantum states as well as output squeezing surpassing gigahertz bandwidths. Furthermore, we show how the same systems also support self‐pulsing and bistability, enabling control of light in both the mean field and noise domains. Our protocol could enable advances in low‐noise communication, cavity QED, and quantum sensing across the electromagnetic spectrum.