β-Zn_3BPO_7非线性光学晶体的光谱特性

The Spectra Character of Nonlinear Optical Crystal β-Zn_3BPO_7

测量了β-Zn3BPO7晶体(001)方向的红外-可见-紫外光波段的透射与反射光谱,从而得到反射谱R透射谱T,以及吸收系数,并得出样品的禁带能隙Eg=3.198 eV。利用太赫兹时域光谱(THz—TDS)测量技术,测量了THz辐射脉冲参考波形和透过样品后的信号波形,进行傅立叶变换和简单的数学处理,得到β-Zn3BPO7样品的介电系数的实部和虚部,以及吸收系数的变化频谱α(ν)。在1.396,2.002,2.476和2.674 THz处,分别存在明显的共振吸收峰。在THz波段的吸收较小,特别是在0.5 T到1.5 T之间,吸收几乎接近于零,而样品在高频端有吸收增大的趋势。

The reflectance and transmittance spectra in the ultraviolet - visible-infrared light （wavelength： 200 nm-2000 nm） were measured, the forbidden band Eg was gotten as 3. 198 eV. Using electro-optic sampling technique and helping with the application of THz time-domain spectroscopy-transmission equipment, the reference THz wave and the signal THz wave have been measured in a range from 0.3 THz to 3.0 THz. The absorption, refractive index and dielectric coefficient have been obtained from Fourier transform. There are some absorption peaks at 1. 396, 2. 002, 2. 476 and 2. 674 THz respectively. The absorption is very small in THz band. Especially from 0. 5 THz to 1.5 THz the absorption is almost closed to zero, and it has the trend of accretion in the higher frequency.