量子阱红外探测器光栅耦合参数的优化

Optimization of grating light coupling parameters for quantum well infrared detectors

基于傅里叶光学的知识,分别对量子阱红外探测器的一维和二维光栅耦合模式进行了研究,得到器件的相对吸收率随波长和光栅周期之比的变化曲线,把此曲线作为优化光栅常数的依据。对于给定峰值波长的探测器,在波长与一维光栅周期之比为1时,吸收率最大;波长与二维光栅周期之比为0.7时,吸收效率最高,结果与已发表的数据相符。此外,还对刻蚀误差的影响进行了讨论,当实际刻蚀的光栅常数与优化的有偏差时,耦合效率降低。

Based on the knowledge of Fourier optics, the grating light coupling models in quantum well infrared detectors were studied.Plots of relative absorption efficiency as a function of the ratio of wavelength to grating period were obtained. Moreover, periods of one and two-dimensional grating , respectively, were optimized according to these curves for the detector with given peak wavelength. The resuits show that the relative absorption efficiency reaches its maximum value when the ratio of wavelength to grating period is 1 for one-dimensional grating, and 0.7 for two-dimensional grating.These results are consistent with published data.In addition, the influence of fabrication errors on absorption efficiency was also discussed. The results conclude that the absorption efficiency decreases with an increase in the fabrication errors.