半导体表面等离子体效应对THz波传输特性的影响

Influence of Photoinduced Surface Plasma in Semiconductor on Transmission Characteristics of THz Wave

本文提出了一种利用激光照射高阻硅来控制硅片中THz波传输特性的方法。利用波长为808nm的激光照射高阻硅产生光生电导来控制硅片对THz波的吸收系数,进而控制硅片中THz波的传输特性,并测量了在光强为1.9W/cm^2的激光照射下硅片对THz波的透射特性。在1.9W/cm^2的激光照射下,0.07cm硅片的THz波透射量减少了20%。实验证明,利用激光控制硅片中的THz波传输是可行的。

A method to control the transmission characteristics of the THz wave in a silicon wafer by using a laser to irradiate the surface of a high resistance silicon （H-Si） wafer is presented. First, the laser at the wavelength, of 808nm is used to irradiate the H-Si wafer so as to let it generate the photolnduced conductance. Then, the photoinduced conductance is used to control the absorption coefficient of the THz wave and hence to control the transmission characteristics of the THz wave in the silicon wafer. The transmission characteristics of the THz wave in the silicon wafer is measured when it is irradiated by the laser with a light intensity of 1.9W/cm2. Under the irradiation by the laser with a light intensity of 1.9W/cm2, the transmission of the THz wave in the 0.07cm silicon wafer is reduced by 20%. The experiment shows that it is feasible to control the transmission of the THz wave in a silicon wafer by using a laser.