Terahertz Radiation From Coherent Phonons Excited In Semiconductors
Terahertz Radiation From Coherent Phonons Excited In Semiconductors
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半导体中激发的相干声子产生的太赫兹辐射
DOI：
10.1109/cleopr.1997.610726
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
Shin
中科院分区：
文献类型：
--
作者：
Masahiko Tani;R. Fukasawa;Hajime Abe;Shuji Matsuura;K. Sakai;Shin
用超快光电导取样探测器研究了碲、碲化铅和碲化镉中相干声子发射的太赫兹辐射。无论不同的晶体结构，对所有样品都观察到了来自红外激活模式的纵向光学（LO）声子振荡的明显相干辐射。此外，在横向光学（TO）声子频率，这不能解释的吸收在发射体积，光谱骤降，观察到所有样品。模型计算表明，进入空气的辐射发射率与进入电介质（半导体）侧的辐射发射率的比例为1/{1+（nd 2 +κd2）nd 3}（nd和κd分别是复折射率的真实的部分和虚部）。因此，增强发射的辐射的相干LO声子和光谱骤降在TO声子频率可以解释为相应的增加和减少的辐射的发射效率的空气，由于…
Terahertz radiation emitted by coherent phonons in Te, PbTe, and CdTe has been investigated by using an ultrafast photoconductive sampling detector. Pronounced coherent radiation originating from the longitudinal optical (LO) phonon oscillations of infrared-active modes was observed for all samples, irrespective of the different crystal structures. In addition, spectral dips at the transverse optical (TO) phonon frequencies, which could not be explained by absorption in the emitting volume, were observed for all samples. The model calculations indicate that the emission rate of the radiation into the air to that into the dielectric (semiconductor) side is scaled by 1/{1+(nd2+κd2)nd3} (nd and κd are the real and imaginary part of the complex refractive index, respectively). Thus, the enhanced emission of radiation by the coherent LO phonons and the spectral dips at the TO phonon frequencies can be explained by the respective increase and reduction of the emission efficiency of the radiation to the air due ...