基于谐波测试法的光导探测器阻抗非线性研究

Photoconductive Impedance Nonlinearity Testing Using the Harmonic Method

摘要:

随着红外技术的发展,红外探测器响应非线性现象及其表征逐渐成为国内外研究的新热点。然而,传统的测试方法无法有效区分线性响应与非线性响应,使得非线性的测试精度受到限制。文章利用谐波信号表征光导探测器的阻抗非线性,通过提取非线性分量排除线性信号的干扰,增加测试的精度。使用该谐波法测试了两个不同材料与结构的探测器,发现所测试的利用液相外延材料制备的探测器由于阻抗非线性产生的谐波信号约是体材料探测器的100倍,这可能是热激发在不同探测器上的效果不一致,导致非线性程度的不同。结合实验和数学分析,证明了该谐波法在光导探测器阻抗非线性测试中的可行性。

Abstract:

With the development of infrared technology, characterizing the response nonlinearity of infrared detectors has become a key focus for domestic and international research. However, traditional test methods cannot effectively distinguish between linear and nonlinear responses, making the accuracy of nonlinear testing limited. By using harmonic signals to characterize the impedance nonlinearity of photoconductive detectors and extract their nonlinear components, the interference of linear signals can be excluded and the accuracy of the tests can be increased. In this study, two detectors of different materials and structures were tested using the harmonic method. The results show that the harmonic signals due to the impedance nonlinearity of the detector prepared from the liquid-phase epitaxial material are approximately 100 times higher than those of the bulk-material detector. This may be due to the inconsistent effect of thermal excitation on different detectors, resulting in different degrees of nonlinearity. The feasibility of the harmonic method in impedance nonlinearity testing of photoconductive detectors is demonstrated by a combination of experimental and mathematical analyses.