Guerrero A Montaña, Nussenzveig P, Martinelli M, Marino A M, Florez H M
Instituto de Física, Universidade de São Paulo, 05315-970 São Paulo, Brazil.
Center for Quantum Research and Technology and Homer L. Dodge Department of Physics and Astronomy, The University of Oklahoma, Norman, Oklahoma 73019, USA.
Phys Rev Lett. 2020 Aug 21;125(8):083601. doi: 10.1103/PhysRevLett.125.083601.
We present the first measurement of two-mode squeezing between the twin beams produced by a doubly resonant optical parameter oscillator (OPO) in an above threshold operation based on parametric amplification by nondegenerate four wave mixing with rubidium (^{85}Rb). We demonstrate a maximum intensity difference squeezing of -2.7 dB (-3.5 dB corrected for losses) with a pump power of 285 mW and an output power of 12 mW for each beam, operating close to the D1 line of Rb atoms. The use of open cavities combined with the high gain media can provide a strong level of noise compression and the access to new operation regimes that could not be explored by crystal based OPOs. The spectral bandwidth of the squeezed light is broadened by the cavity dynamics, and the squeezing level is robust for strong pump powers. Stable operation was obtained up to 4 times above the threshold. Moreover, operation of the OPO close to the atomic resonances of alkali atoms allows a natural integration into quantum networks, including structures such as quantum memories.
我们展示了基于与铷（(^{85}Rb)）的非简并四波混频进行参量放大的双共振光学参量振荡器（OPO）在阈值以上运行时，对其产生的孪生光束之间双模压缩的首次测量。我们证明，在泵浦功率为285 mW且每束光输出功率为12 mW的情况下，在接近铷原子D1线的条件下运行时，最大强度差压缩达到 -2.7 dB（经损耗校正后为 -3.5 dB）。开放腔与高增益介质的结合使用能够提供强大的噪声压缩水平，并能进入基于晶体的OPO无法探索的新运行模式。压缩光的光谱带宽因腔动力学而变宽，并且在强泵浦功率下压缩水平很稳健。在高于阈值4倍的情况下仍能实现稳定运行。此外，OPO在接近碱金属原子的原子共振处运行，使得它能够自然地集成到量子网络中，包括量子存储器等结构。
