Donati Silvano, Martini Giuseppe, Norgia Michele
Università di Pavia, Dipartimento di Elettronica,Via Ferrata 1, 27100, Pavia, Italy.
Opt Express. 2007 Dec 24;15(26):18066-75. doi: 10.1364/oe.15.018066.
We propose an array of non-imaging micro-concentrators as a mean to recover the loss of sensitivity due to area fill-factor. This is particularly important for those image photo detectors in which complex circuit functions are required and a substantial fraction of the pixel area is consumed, like e.g., 3D camera, SPAD arrays, fluorescence analyzers, etc., but also in CMOS sensors. So far, the low fill-factor was an unacceptable loss of sensitivity precluding from the development of such devices, whereas by using a concentrator array a recovery is possible, up to the inverse square of numerical aperture of the objective lens. By ray tracing, we calculate the concentration factors of several geometries of non-imaging concentrator, i.e., truncated cone, parabolic and compound parabolic, both reflective and refractive. The feasibility of a sizeable recovery of fill-factor (up to 50) is demonstrated.
我们提出了一系列非成像微聚光器，作为一种弥补因面积填充因子导致的灵敏度损失的方法。这对于那些需要复杂电路功能且像素面积有很大一部分被占用的图像光电探测器尤为重要，例如3D相机、单光子雪崩二极管（SPAD）阵列、荧光分析仪等，在CMOS传感器中也是如此。到目前为止，低填充因子是不可接受的灵敏度损失，阻碍了此类器件的发展，而通过使用聚光器阵列则有可能实现灵敏度恢复，最高可达物镜数值孔径的平方反比。通过光线追踪，我们计算了几种非成像聚光器几何形状（即截头圆锥、抛物线形和复合抛物线形，包括反射型和折射型）的聚光因子。证明了大幅恢复填充因子（高达50）的可行性。
