针对二氧化钒(VO 2)薄膜在可调谐太赫兹功能器件中的应用,采用磁控溅射法在 K9玻璃衬底上制备了 VO 2薄膜,并用 X 射线衍射(XRD)对薄膜的晶相进行表征。利用配备加热装置的太赫兹时域光谱系统(THz-TDS)研究了薄膜样品在变温过程中的 THz 反射、透射光谱特性及其变化规律。实验结果表明,随着加热温度的升高,VO 2薄膜发生半导体-金属相变并对宽频段 THz 波产生显著的调制作用。调制深度明显依赖于 THz 频率,薄膜样品对 THz 波反射功率、透射率的幅度调制深度在0.3~0.5 THz 范围波动较大;对THz 波的透射率在低频处较大,高频处较小,调制深度在35%~65%之间变化。该薄膜制备简单,质量高,可应用于太赫兹开关和调制器等功能器件。
For the applications of vanadium dioxide (VO 2 )thin film in terahertz tunable functional devices,the vanadium dioxide VO 2 thin film was prepared by magnetron sputtering technique on K9 glass substrate,and the crystal structure was char-acterized by X-ray diffraction (XRD).Spectral characteristics and their variations of terahertz (THz)reflection and transmission signal passing through the sample at different temperatures were studied by the THz time domain spectroscopy system (THz-TDS)equipped with heating device.The experimental results indicated that the semiconductor-metal transition of VO 2 thin film occurred with the increase of the heating temperature and showed excellent modulation to the broadband THz wave.The modula-tion depth was dependent on the THz frequency.The THz wave amplitude modulation depth of reflection power and transmission showed remarkable fluctuation in the band of 0.3-0.5 THz.The transmittance of THz wave was larger in the low frequency band than that in the high frequency band,and the modulation depth varied in the range of 35%-65%.The thin film was prepared sim-ply and had high quality,which can be applied to THz modulator functions such as devices and switches.