%0 Journal Article
%T THz spectra of five borates crystals
%A BiHui Hou
%A YaLi Wang
%A YiCheng Wu
%A Hua Chen
%A Li Wang
%A PengZhen Fu
%A FengYan Liu
%J Chinese Science Bulletin
%@ 1861-9541
%D 2008
%I 
%R 10.1007/s11434-007-0411-x
%X Terahertz spectral responses have been studied for five borate crystals Na5[B2P3O13] (NBP), Zn3BPO (ZBP), SrB4O7 (SBO), Na3La9O3(BO3)8 (NLBO) and PbB4O7 (PBO). It is found that the samples had good transmission in 0.25¨C1.5 THz region. Both SBO and NLBO have an absorption coefficient less than 10 cm 1. Among them, SBO has not only the smallest absorption coefficient but also a very flat dispersion in the frequency region under investigation. Distinct resonance absorption peaks are observed for ZBP at v 1 = 1.4 THz, v 2 = 2.0 THz and SBO at v = 2.4 THz. In the spectrum of PBO, two abnormal dispersions appear in the frequency regions 1.44¨C1.74 and 2.2¨C2.5 THz. The absorption coefficients and refraction indices of the five crystals are extracted from the THz time-domain (THz-TDS) spectra in 0.25¨C2.5 THz region. The properties and origins of the spectral responses are addressed.
%K borates crystals
%K THz spectroscopy
%K lattice vibrations
%K optical phonon
%U http://link.springer.com/article/10.1007/s11434-007-0411-x