Photonics Research, 2016, 4 (3): 03000A16, Published Online: Sep. 29, 2016
Nonlinear terahertz metamaterial perfect absorbers using GaAs [Invited] Download: 1081次
Far infrared or terahertz Far infrared or terahertz Metamaterials Metamaterials Nonlinear optical Nonlinear optical
Abstract
We investigate the nonlinear response of terahertz (THz) metamaterial perfect absorbers consisting of electric split ring resonators on GaAs integrated with a polyimide spacer and gold ground plane. These perfect absorbers on bulk semi-insulating GaAs are characterized using high-field THz time-domain spectroscopy. The resonance frequency redshifts 20 GHz and the absorbance is reduced by 30% as the incident peak field is increased from 30 to 300 kV/cm. The nonlinear response arises from THz field driven interband transitions and intervalley scattering in the GaAs. To eliminate the Fresnel losses from the GaAs substrate, we design and fabricate a flexible metamaterialsaturable perfect absorber. The ability to create nonlinear absorbers enables appealing applications such as optical limiting and self-focusing.authors would like to thank the Boston University Photonics Center for technical support.
Xiaoguang Zhao, Jingdi Zhang, Kebin Fan, Guangwu Duan, Grace D. Metcalfe, Michael Wraback, Xin Zhang, Richard D. Averitt. Nonlinear terahertz metamaterial perfect absorbers using GaAs [Invited][J]. Photonics Research, 2016, 4(3): 03000A16.