Combination of Kramers-Kronig transform and time-domain methods for the determination of optical constants in THz spectroscopy
Combination of Kramers-Kronig transform and time-domain methods for the determination of optical constants in THz spectroscopy
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DOI：
10.1016/j.vibspec.2012.01.017
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发表时间：
2012-05-01
影响因子：
2.5
通讯作者：
Heise, H. Michael
中科院分区：
文献类型：
--
作者：
Herrmann, Michael;Platte, Frank;Heise, H. Michael
吸收和反射光谱已成功地用于物质识别，这也适用于太赫兹光谱范围。对于光谱学，Kramers-Kronig变换（KKT）是一种强大的工具，可以从吸收或反射测量中确定波浪线上的复折射率（n）（分别具有k，n吸收和折射率）。通过太赫兹时域光谱（THz-TDS），用短脉冲辐射探测材料。该检测在电场的幅度和相位上对样品敏感。因此。与传统的傅里叶变换光谱相比，THz-TDS光谱可以提供更多的信息，通过傅里叶变换光谱测量功率谱。例如，在透射测量的情况下，存在公式，通过该公式，频率相关的复折射率直接从时间相关的电场（波形）计算，而不需要KKT。在反射实验的情况下，可以对频率相关的相位角进行类似的计算;在这里，KKT可以帮助恢复基本参数。我们提出了一个KKT和TDS方法的组合计算光学常数在太赫兹制度。(C)2012爱思唯尔有限公司版权所有。
Absorption and reflection spectra have successfully been used for substance identification, which is also applicable to the THz spectral range. For optical spectroscopy, the Kramers-Kronig transformation (KKT) is a powerful tool to determine the complex refractive index (n) over tilde (with k, n absorption and refractive indices, respectively) from either an absorption or reflection measurement. By terahertz time-domain spectroscopy (THz-TDS) materials are probed with short pulses of radiation. The detection is sensitive to the sample on both the amplitude and the phase of the electrical field. Thus. THz-TDS spectroscopy can provide more information than conventional Fourier-transform spectroscopy, by which a power spectrum is measured. In the case of transmission measurements, for instance, formulae exist by which the frequency-dependent complex refractive index is directly calculated from the time-dependent electrical field (waveform) without the necessity of a KKT. In the case of reflection experiments, a comparable computation is possible for the frequency-dependent phase angle; here a KKT can help to recover essential parameters. We present a combination of KKT and TDS methods for the calculation of optical constants in the THz regime. (C) 2012 Elsevier B.V. All rights reserved.