I类自发参量下转换光谱圆环空间分布

Space Distribution of Type-ΙSpontaneous Parametric Down-conversion Spectra Circle

理论模拟了I类自发参量下转换产生的相关光子光谱圆环的空间辐射角度及光强分布,搭建了相关光子圆环光强分布的实验测量装置,该装置利用355nm连续激光器泵浦BBO晶体产生I类自发参量下转换相关光子圆环,使用CMOS传感器作为相关光子圆环探测单元,通过2×2维点阵扫描方法探测了完整的相关光子圆环,测量的光谱分布为430～860nm.实验结果表明：测量的相关光子圆环直径与理论值符合较好;I类自发参量下转换过程产生的相关光子在空间呈同心圆环分布;相关光子光谱具有宽光谱分布特点.

As a single photon state,the correlated photon is often applied to quantum communication and optics metrology domain.The study of the spectral radiation and intensity distribution of the photon has agreat significance for the broad-band radiometric calibration.The space distribution of the correlated photon spectra circle generated by type-I Spontaneous Parametric Down Conversion（SPDC） was simulated theoretically.Based on the simulation,the corresponding experimental measurement system was established.In this system,355 nm laser is set to pump the BBO crystal,the type-I correlated photon spectra circle is detected by a Complementary Metal Oxide Semiconductor（CMOS）camera.The dot-matrix scanning method is used to record the circle.The spectral distribution of the measurements is430nm～860nm.The results show that the spectra circle diameters of experimental results are highly consistent with the theoretical ones,the spectra circle distribution of type-I SPDC is homocentric and the spectra of the correlated photon has a broad band.