利用太赫兹时域光谱系统研究温度对Ga As基底上生长的太赫兹亚波长金属结构的透过率及共振特性的影响。实验发现,温度从低温80 K升高至380 K,样品的透过率逐渐降低,且低频共振频率处有轻微的红移现象。通过研究共振带区域及远离共振带区域的透过率情况,分析了总体透过率降低的根本原因在于温度升高导致Ga As基底的本征载流子浓度升高;共振凹陷减弱是由于基底载流子的变化致使透过率升高形成的;红移现象的产生是由于温度升高导致样品折射率增大。此外,该研究可以为太赫兹范围的功能器件在实际应用和生产制造中提供有意义的参考。
By using terahertz time domain spectroscopy(THz-TDS), the transmission and resonance properties of terahertz subwavelength metal structures at different temperatures were studied. The transmission of "U "- and "E "- shaped structures decreased gradually with temperature increasing from80 K to 380 K. Meanwhile, the low resonance frequency showed a slight red-shift. Through the study of temperature-dependent transmission spectra at resonance and non-resonance regions, the phenomenon of transmission decreasing was attributed to the increasing of carrier concentration in Ga As substrate. The weakened resonant strength originated from the resonate quench by temperature-generated carriers in substrate. The red-shift was due to the increase of refractive index. The investigation could provide some meaningful guides in pratical application of terahertz functional devices.