Guo Jun, Cai Chunxiao, Ma Long, Liu Kui, Sun Hengxin, Gao Jiangrui
Opt Express. 2017 Mar 6;25(5):4985-4993. doi: 10.1364/OE.25.004985.
Nonclassical beams in high order spatial modes have attracted much interest but they exhibit much less squeezing and entanglement than the fundamental spatial modes, limiting their applications. We experimentally demonstrate the relation between pump modes and entanglement of first-order Hermite Gauss modes (HG entangled states) in a type II OPO and show that the maximum entanglement of high order spatial modes can be obtained by optimizing the pump spatial mode. To our knowledge, this is the first time to report this. Utilizing the optimal pump mode, the HG mode threshold can be reached easily without HG oscillation and HG entanglement is enhanced by 53.5% over HG pumping. The technique is broadly applicable to entanglement generation in high order modes.
高阶空间模式下的非经典光束已引起了广泛关注，但与基模相比，它们表现出的压缩和纠缠要少得多，这限制了它们的应用。我们通过实验证明了II型光学参量振荡器中泵浦模式与一阶厄米高斯模式（HG纠缠态）的纠缠之间的关系，并表明通过优化泵浦空间模式可以获得高阶空间模式的最大纠缠。据我们所知，这是首次报道这一结果。利用最优泵浦模式，可以轻松达到HG模式阈值而不会出现HG振荡，并且与HG泵浦相比，HG纠缠增强了53.5%。该技术广泛适用于高阶模式下的纠缠产生。
