研究了一种简单实用的光学探测器非线性系数测量方法。采用两颗红外发光二极管(LED)，配用数字源表控制LED 光源的开关和驱动电流值，通过光束叠加法在4 个数量级内实现在特定红外波长上光学探测器非线性系数的测量，波长位置由LED 发光峰决定。采用红外940 nm LED，在恒温实验室条件下，进行了LED 持续点燃的稳定度的研究。当点燃时间在1 min 到10 min 内，光源到达探测器的辐射通量变化的相对标准偏差值不大于0.022%。进行了重复条件下红外LED 辐射通量水平复现性的考察。短时间内重复点燃10次，辐射量值变化的相对标准偏差不超过0.044%。进行了校准结果的测量不确定度评定，基于940 nm LED 的非线性系数校准结果的扩展不确定度为0.07% (k=2)。

A simple and practical technique is studied to develop a near- infrared nonlinearity coefficient measurement for optical detector. Two infrared LEDs are used, and two source meters are adopted to control the LEDs and their driving currents. Using flux-addition method, the proposed method achieves the measurement of nonlinearity coefficient within four orders of magnitude at certain wavelength, which is determined by the emission peak of LED. The 940 nm LED is used as an example. The room temperature is controlled and the infrared LEDs as the light sources are quite stable. When the ignition time ranges from 1 min to 10 min, the relative standard deviation of the radiation flux is not greater than 0.022%. The reproducibility of the LED flux is also studied. The LED is turned on and off 10 times, and the relative standard deviation of the radiation flux does not exceed 0.044% at different flux levels. The measurement uncertainty is discussed and evaluated. The expanded measurement uncertainty of the calibration results is 0.07% (k=2).