论文标题
I型SPDC生成的两种阶段
Gouy phase of type-I SPDC-generated biphotons
论文作者
论文摘要
我们考虑一个双高斯近似值，以描述通过I型自发参数下调（SPDC）过程在非线性晶体中产生的双光子（也称为Biphoton）的波函数。我们发现，波函数在传播时会发展出一个花序相，这取决于通过雷利长度的两光子相关性。我们评估了协方差矩阵，并表明对数负性可用于量化高斯州的纠缠，尽管依赖雷利（Rayleigh）并不取决于传播距离。此外，我们表明，由于这些数量与瑞利长度相关，因此两光子纠缠可以连接到双孔岩相。然后，我们使用薄透镜将双重高斯双波子波函数聚焦，并计算出与D. Kawase等人的实验数据合理一致的花序相。发表在参考文献中。 [1]。
We consider a double Gaussian approximation to describe the wavefunction of twin photons (also called a biphoton) created in a nonlinear crystal via a type-I spontaneous parametric downconversion (SPDC) process. We find that the wavefunction develops a Gouy phase while it propagates, being dependent of the two-photon correlation through the Rayleigh length. We evaluate the covariance matrix and show that the logarithmic negativity, useful in quantifying entanglement in Gaussian states, although Rayleigh-dependent, does not depend on the propagation distance. In addition, we show that the two-photon entanglement can be connected to the biphoton Gouy phase as these quantities are Rayleigh-length-related. Then, we focus the double Gaussian biphoton wavefunction using a thin lens and calculate a Gouy phase that is in reasonable agreement with the experimental data of D. Kawase et al. published in Ref. [1].
