中文摘要：

针对近些年发展的相关光子定标方法在光学计量方面的应用需求，在理论上分析了I类非共线自发参量下转换（SPDC）光谱的分布，并考虑完全相位匹配和相位失配两种情况下，355nm连续激光光源泵浦I类非共线BBO晶体产生自发参量下转换信号光的分布曲线。数值模拟结果表明，这两种情况下，I类非共线SPDC产生的光谱分布一致。最后设计了SPDC光谱分布测量实验，实验表明，I类非共线SPDC光谱分布与数值模拟结果相同。

英文摘要：

With the application demand of optical metrology based on correlated photons method in recent years, spectral distribution of type-I noncollinear spontaneous parametric down-conversion （SPDC） is theoretically analyzed. Two different cases including ideal phasing-matching and nonideal phasing-matching are considered, SPDC spectral distribution curve is formed by 355 nm CW laser pumping type-I noncollinear BBO crystal, and numerical simulation results show that two cases have almost the same spectral distribution. Lastly measurement experiment of SPDC spectral distribution is designed. The experiment shows type-I noncollinear SPDC spectral distribution is in good agreement with numerical simulation.