摘要
以GaAs材料为例,研究了半导体远红外反射镜中的反射率和相位.通过拟合不同掺杂浓度下样品的远红外反射谱,得到了自由载流子的弛豫时间随掺杂浓度变化的经验公式,并把该规律应用到数值计算中.详细讨论了反射镜的结构和材料参数对反射率R和相位φ的影响.根据腔体内吸收率最高的判据得到了最优的反射镜的参数,并计算了这种优化后的反射镜的波长选择特性.最后,通过远红外反射光谱的测量,从实验上验证了这种反射镜的实际效果.所得结论为半导体远红外器件中的反射镜设计提供了参考.
We have carried out an in-depth investigation on the reflecfivity R and phase shift φ of a novel semiconductor mirror, which can be applied in the far-infrared （FIR） spectral range. By fitting FIR reflection spectra of the GaAs material with different doping concentrations, empirical formulas are obtained for the doping concentration-dependent carrier relaxation time τ of n-GaAs and p-GaAs. The effects of structure and material parameters on the reflectivity and the phase shift of the mirror are analytically studied on the basis of the deduced formulas. All the related parameters of the mirror are further optimized, and the corresponding wavelength selectivity is calculated according to the highest absorption in the detector cavity. The experimental FIR reflection result confirms the theoretical simulation, revealing the unique properties of this mirror, which establishes the basis of optimum designing of various FIR mirrors.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2007年第4期2415-2421,共7页
Acta Physica Sinica
基金
国家自然科学基金(批准号:10125416
10304010
60576067)
上海市青年科技启明星跟踪计划(批准号:05QMH1411)资助的课题.~~
关键词
远红外反射镜
反射率
相位
far-infrared mirror, reflectivity, phase
