Development of ultra-broadband terahertz time domain ellipsometry
Development of ultra-broadband terahertz time domain ellipsometry
复制标题
超宽带太赫兹时域椭偏仪的研制
DOI：
10.1117/12.2186928
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Chiko Otani
中科院分区：
文献类型：
--
作者：
Masatsugu Yamashita;Chiko Otani
我们开发了一种反射式超宽带太赫兹时域光谱椭偏仪，覆盖的频率范围从0.5到30太赫兹。该系统采用两种非线性光学晶体GaP和GaSe分别作为太赫兹和中红外光源，探测器采用基于硅衬底上低温生长GaAs（LT-GaAs）外延层的光电导天线开关。通过切换发射器，可测量的频率范围可以很容易地从0.5-7.8 THz范围改变到7.8-30 THz范围，而无需额外的光学对准。我们测量了p型InAs晶片的介电函数和氧化铟锡（ITO）薄膜的复电导率。ITO薄膜的载流子密度和迁移率与Hall实验结果吻合较好
We developed a reflection type ultra-broad band terahertz time-domain spectroscopic ellipsometry covering the frequency range from 0.5 to 30 THz. The system utilizes two nonlinear optical crystals of GaP and GaSe as terahertz and mid-infrared sources, respectively, and employs a detector based on a photoconductive antenna switch using a low temperature grown GaAs (LT-GaAs) epitaxial layer transferred on Si substrate. By switching the emitter, the measurable frequency range can be easily changed from the 0.5-7.8 THz range to the 7.8-30 THz range without additional optical alignment. We measured the dielectric function of a p-type InAs wafer and the complex optical conductivity of an indium tin oxide (ITO) thin film. The obtained carrier density and the mobility of the ITO thin film show good agreement with that obtained by the Hall