当用1.55微米飞秒激光脉冲照射时，从（111）切割的锑化铟和砷化铟晶体产生太赫兹脉冲。

Terahertz pulse generation from (111)-cut InSb and InAs crystals when illuminated by 1.55-μm femtosecond laser pulses.

作者信息

Nevinskas I, Vizbaras K, Trinkūnas A, Butkutė R, Krotkus A

出版信息

Opt Lett. 2017 Jul 1;42(13):2615-2618. doi: 10.1364/OL.42.002615.

DOI:10.1364/OL.42.002615

Abstract

Terahertz (THz) pulse generation from p-InAs, p-InSb, and n-InSb epitaxial layers are investigated using 1.55-μm wavelength femtosecond laser pulses for photoexcitation. The samples are of (111) crystallographic orientation resulting in anisotropic photoconductivity. Experiments have shown that THz generation in InAs is mainly due to anisotropic photocurrent in the surface electric field while a dominant mechanism in InSb is optical rectification. At high optical excitation fluencies, InSb is more efficient than p-InAs. In the presence of an external magnetic field, (111) InSb has exhibited promising viability as an alternative to the photoconductive antenna emitter in a THz time-domain-spectroscopy (THz-TDS) system.

摘要

利用波长为1.55μm的飞秒激光脉冲进行光激发，研究了p-InAs、p-InSb和n-InSb外延层产生太赫兹（THz）脉冲的情况。样品具有（111）晶体取向，导致光导率呈各向异性。实验表明，InAs中太赫兹的产生主要归因于表面电场中的各向异性光电流，而InSb中的主要机制是光学整流。在高光激发通量下，InSb比p-InAs更有效。在存在外部磁场的情况下，（111）InSb在太赫兹时域光谱（THz-TDS）系统中作为光导天线发射器的替代物已展现出良好的可行性。