利用KTiOPO。(KTP)材料非线性系数d^33对应的二阶非线性O-类准相位匹配,理论上设计构造了一种周期极化KTiOPOa晶体(PPKTP),当晶体温度为20℃时,晶体准相位匹配格子的周期为10.70μm。波长为550nm的激光泵浦由该晶体组成的光学参量振荡器能产生含852nm信号光和l550nm的闲置光的双色纠缠,其中信号光对应cs原子吸收线,闲置光I550nm对应光纤通讯波长。该纠缠光对量子信息网络和原子信息存储有非常重要的意义。
In this paper, we theoretically design the second-order nonlinear periodically poled KTiOPO4 crystal (PPKTP) by the 0-type quasi phase matching of nonlinear coefficients d33 . The period of PPKTP is 10.7 microns at 20 centigrade degree. The bicolor entanglement of 852 nm signal light and 1550 nm idle light can be generated when an optical parametric oscillator of the PPKTP is pumped by 550 nm light. One of entangled beams corresponds to Cs atomic transition line, the other corresponds to optical fiber communication wavelength. The entanglement is of importance for the quantum information network and atomic information storage.