中文摘要：

研究了窄带隙材料InAs和三种不同掺杂浓度的InN在不同抽运光强激发下产生太赫兹（THz）波的辐射特性.实验结果表明：在相同的抽运光强下,InN和InAs辐射的THz信号强度在同一量级,InAs较InN辐射效率要高一些.随着抽运光强的增大,这几种材料的发射光谱变得更宽,当抽运光增大到一定强度时,它们的发射光谱半极大值全宽（HMFW）趋于恒定.InN比InAs更容易在较低功率的抽运光作用下获得宽带太赫兹光谱.研究也表明,不同掺杂浓度对辐射THz波的强度及辐射效率有很大影响.这项研究对于探索半导体表面辐射太赫兹波的机理具有一定的科学意义,同时也为寻找低成本和高效率的THz辐射源提供一定的参考.

英文摘要：

The characteristics of terahertz（THz） radiations from the surfaces of two kinds of narrow-band semiconductors InN and InAs excited by femtosecond laser pulses with different pump powers（from 10 to 320mW） are investigated experimentally.The results show that InAs can irradiate a stronger THz signal than that of InN under the same pump power so its radiation efficiency is higher.However,the spectral widths of THz radiations from these semiconductor surfaces increase with the increase of pump power.When the intensity of pump laser is high enough,the spectral Half-MaximumFull-Width（HMFW） of THz radiation tends to be a constant.Compared with InAs,InN can reach this constant HMFW THz spectrum at a lower pump power.This research is significant for investigating the THz radiation mechanism from semiconductor surfaces,and it is also a good reference for exploring a THz radiation source with low cost and high efficiency.