中文摘要：

基于自发参量下转换产生相关光子的定标方法具有基于客观物理效应、无需溯源的优点,有望成为未来光辐射定标技术发展的新趋势.目前利用该技术定标光子计数型探测器的最低不确定度为0.18%,仍有进一步提高定标精度的潜力.由于相关光子圆环具有高光子速率特性,能够显著提高定标过程中信号光和空闲光的光子速率.为了提高该方法定标精度及利用相关光子定标模拟探测器,研究相关光子圆环的时间相关特性具有非常重要的意义.本文理论计算了Ⅰ类自发参量下转换产生的宽谱段相关光子圆环出射角度的空间分布,使用ZEMAX光学设计软件设计了用于接收宽谱段（450—1000 nm）相关光子圆环并能够滤除抽运光的光学系统,利用微光相机拍摄到了光学系统接收的430—860 nm波段的相关光子圆环;搭建了双通道相关光子圆环时间相关特性测量系统,观测到了1 m W连续激光器抽运非线性晶体产生的685 nm和736.89 nm波段相关光子圆环对具有明显的符合峰现象,从实验上验证了Ⅰ类自发参量下转换产生的相关光子圆环具有时间相关特性.

英文摘要：

The optical radiometric calibration method based on correlated photons generated by spontaneous parametric down-conversion（SPDC） is a promising method, because it is based on the basic physical phenomena and does not need radiometric traceability. At the present, the SPDC calibration technology is applicable for the photon-counting detector with a highest calibration accuracy of 0.18%. More and more researchers are making effort to improve its calibration accuracy and expand its applicable targets to analog detectors. Correlated photon circles have the high photon rate characteristic. The photon rates of signal and idle light can be improved significantly by using correlated photon circles in calibration. It has very important significance to study the time-correlation characteristic of correlated photon circles.In this paper, the spatial distribution of emission angle of the broadband（450–1000 nm） correlated photons generated by type-Ⅰ spontaneous parametric down-conversion is presented through the theoretical calculations. The ZEMAX？ optical software is used to design the optical system which can receive the broadband correlated photon circles and remove the pump laser which is the main source of stray light. The 355 nm wavelength laser is used to pump β-barium borate（BBO）crystal to generate the broadband correlated photon circles. A low-light-level CMOS camera is used to adjust and align the opt-mechanical system. Finally, the 430 nm–860 nm correlated photon circles are received by the optical system and detected by the low-light-level CMOS camera. An experimental measurement system is established to measure the time-correlation characteristics of 685 nm and 736.89 nm correlated photon circles. Using 1.0 m W continuous-wave laser to pump BBO crystal, a coincidence peak is observed evidently. The results show that the correlated photon circles generated by type-Ⅰ SPDC have the characteristics of time-correlation and high photon rates. It can be conductive to improving optical radiometric