基于三阶非线性Kerr效应在光纤中产生非线性现象的理论,利用零色散位移光纤中的自发四波混频通过两种实验装置产生了纠缠光子:一种是采用脉冲光抽运由光纤构成的Sagnac光纤环;另一种是采用脉冲光直接抽运一段光纤.通过对不同装置下实验结果的比较,总结了产生高纯度纠缠光子所需的实验条件,并指出了两种装置各自的优缺点.这为研制适用于量子通信的全光纤纠缠光源和单光子源奠定了基础.
Based on the theory of third-order nonlinear Kerr effect in optical fiber,we experimentally demonstrate the generation of photon pairs by exploiting spontaneous four-wave mixing.The photon pairs are produced by pumping a fiber Sagnac loop and a piece of straight fiber with a pulsed laser,respectively.By comparing the experimental results,we analyze how to optimize the experimental parameters to obtain entangled photon pairs with high purity.Our results are useful for developing the all-fiber source of photon pairs and single photon source,which are well suited for quantum communication.