基于光子晶体光纤关联光子对频谱特性的研究

Study on Spectral Characteristics of Correlated Photon Pairs Based on Photon Crystal Fiber

为了研究光子晶体光纤在 800 nm波段关联光子对的频谱特性,基于自发四波混频得到了脉冲抽运光产生的光子对的相位匹配函数和频谱函数。数值计算、证明闲频光中心波长取796 nm时的频谱对称性最好;在假设闲频光频率为单一频率的前提下,利用简化频谱函数的表达式,通过改变光子晶体光纤零色散点色散斜率和非线性系数,以及抽运光的入射中心波长,进一步讨论了抽运光和光子晶体光纤参数变化对信号光和闲频光频谱函数的影响及变化规律。提出了有利于产生高纯度纠缠光子对的光纤参数和抽运光参数,结果对于在800 nm波段发展光子晶体光纤纠缠光子源的实验具有指导和参考意义。

The phase-matching function and spectral function of spontaneous four-wave mixing in the fiber pumped by picoseconds pulse are derived, to study spectral characteristics of correlated photon pairs at 800 nm based on photon crystal fiber （PCF）, The calculation result shows that the optimized spectral symmetry can be achieved by choosing the idler wavelength at 796 nm in the fiber. By using the simplified spectral function, the evolved effects and changing law of the signal light and idle light, were discussed under the condition of the idler light with a single frequency, by changing the dispersion slope at the zero dispersion wavelength, the nonlinear coefficient and the central wavelength of pump pulse. Parameters in favor of high purity photon pairs were presented. These results provide reference for developing entangled photon sources based on photon crystal fiber at 800 nm wave band.