The Research Of Terahertz Modulation Characteristics On Subwavelength Metal Structures

With the increasing maturity of terahertz sensors and terahertz sources, the compact structure of light control or electronic control device to control THz beam propagation, has become a new hotspot in terahertz field.Due to the electromagnetic properties of metamaterials in the abnormal solid physics, materials science, optics and other fields began to be more widely favored.In the reported terahertz modulator articles, this array of subwavelength metal structures modulation technique is the most prospects for development.In this paper, the terahertz spectral properties of several arrays of subwavelength metal structures and semiconductor materials have been researched.This first chapter of this article briefly introduces the research background and significance of the subject. The second chapter describes in detail terahertz time-domain spectroscopy and optical pumping THz technology. The third chapter introduces the semiconductor materials under continuous light and pulsed light source terahertz wave transmission characteristics and found that with the increase of the optical pump power THz transmittance continue to decrease, and found that pulsed light irradiation the modulation depth of the semiconductor material than the continuous light source is high. The fourth chapter studies the subwavelength metallic split ring resonators terahertz transmission characteristics of the structure and the metal grating, through simulation and experimental study of a single aperture ring, double ring opening terahertz spectral characteristics Wada-shaped structure; and different opening ring resonator structure, and were compared and found different effects ring opening of the number and position of the absorption peak at the frequency, the greater the opening of the ring structure of the capacitance value, the lower the peak frequency, whereas higher; we researched the subwavelength metal grating transmission characteristics of terahertz wave band, the experimental results showed that since the polarization properties of the grating, the electromagnetic wave that the electric field perpendicular to the grating direction has transmission characteristics and that the electric field parallel to the grating has passive effect; Rayleigh anomaly reduced terahertz transmission at the frequency of1.5THz, where is a transmission valley. In chapter5, we summarize the work achievements and discuss.