基于太赫兹等离激元的半导体表面生化薄膜光谱检测（英文）

Spectrum analysis of bio-chemical thin films on the surface of a semiconductor by terahertz surface plasmon polaritons

提出了一种利用太赫兹表面等离激元对放置在半导体表面的生化薄膜进行光谱测量的新方法.从理论上证明了半导体材料对其传输的太赫兹表面等离子体波具有较强的表面束缚性,从而提高太赫兹波与半导体表面生化薄膜之间的相互作用.通过采用太赫兹时域光谱测量系统,从实验上分别得到了洋葱表皮的太赫兹表面等离子体波和自由空间太赫兹波透射波谱.实验结果表明,当测量对象是厚度仅为自由空间太赫兹波波长约1%的单层洋葱表皮时,表面等离子体波的透射波谱与自由空间太赫兹波透射波谱相比具有更加多的特征吸收峰.

A new method for measuring terahertz （THz） transmission spectra of bio-chemical thin films placed on the surface of a semiconductor by terahertz surface plasmon polaritons （SPPs） was proposed. A strongly confined surface plasmon in the terahertz frequency range on the surface of semiconductor was theoretically proved, which can be used to enhance the light-matter interaction with bio-chemical layers above the semiconductor surface. By employing a free-space THz time-domain spectroscopy （TDS） system, the transmission power spectra of onion ep- idermis films with free space transmission and SPP transmission, respectively, were experimentally obtained. Ex- perimental results show that SPP transmission spectra represent many characteristic absorption peaks for a layer of onion epidermis film, which are more than 100 times thinner than the free space wavelength of the terahertz wave.