Large-scale array of squeezed light and synchronization using atomic vapor

Quantum light sources such as squeezed light are essential for quantum information science and technologies, but the scalable production of multiple beams of them remains a challenge. Here, we experimentally demonstrate a novel approach to the generation of a large spatial array of polarization-squeezed light beams via atomic-coherence-enhanced nonlinear optical processes using a single atomic vapor cell. Unlike schemes based on independent squeezing generators, the squeezing dynamics of each channel here are governed by a common collective ground-state atomic coherence, produced by all input beams, homogenized by the thermal motion of the atoms, and protected against wall collisions by a paraffin coating. Consequently, the optical states of all channels are coupled and regulated by each other via the moving atoms, leading to synchronization behavior. We realized a 30-beam array of polarization squeezed state with 2.03 ± 0.02 dB of squeezing, experimentally verified the synchronization, and observed improved purity of the squeezed state as well as the system's response to perturbations when the size of the array increases. This work provides a pathway towards scalable high-performance quantum light sources for applications in precision measurement, quantum imaging and quantum information processing.