利用兆赫波時析光譜研究摻碲硒化鎵晶體在不同温度下之電磁特性

Abstract

在本論文中，利用自行架設之兆赫波時間解析光譜系統對摻碲硒化錠晶體進行不同温度的量測，進而獲得0.2 THz至2.5 THz電磁波段範圍內之複數折射率，吸收係數和介電常數。除此之外，晶體中層與層間在0.585 THz的剛性層振動模態將隨著碲摻雜而漸漸受到破壞，取而代之的為1.766 THz的晶體層內振動模態。另外，藉由聲子模態隨温度變化中出現的藍移現象可以進一步驗證和解析碲在硒化鎵晶體中所扮演的角色。

Since the tellurium-doped gallium selenide crystals has good potential in phase-matching applications, the homemade terahertz time-domain spectroscopy technique is employed to investigate the physical properties like complex refractive indices and absorption coefficients within the electromagnetic wave range of 0.2 THz to 2.5 THz. The deformation of the rigid layer mode at 0.58 THz, and the formation of the tellurium-induced layer vibrational mode at 1.76 THz were clearly observed in absorption spectra. Moreover, the role of tellurium-doping in GaSe crystals could be revealed from the temperature-dependent blue shift of the rigid layer mode and tellurium-induced layer vibrational mode.