In this paper, a high transmission metasurface for subwavelength focusing of terahertz waves was proposed. A full 2π phase coverage with high transmission at target frequency was designed by varying the lengths of the cross resonators. The high transmission characteristics of the resonators were analyzed and the performance of the focusing was also discussed. The results show that the maximum transmission of the resonators reaches 0.92 and the terahertz wave can be focused with at the focusing point of a full width at half-maximum of 143 μm, which agrees well with the full width at half-maximum of 139 μm obtained by Huygens' principle. This device with the characteristics of flexible, thin and easy-integration exhibits the potential applications in THz imaging and communications, and also can be extended in the design of other planar THz components easily.
Optically tunable negative refractive metamaterials composed of electric response split-ring resonator (eSRR) and magnetic response split-ring resonator (mSRR) are theoretically investigated in terahertz (THz) region. A negative refractive band is achieved when both the eSRR and mSRR are fabricated on one substrate. Meanwhile, the optically tunable response is realized by filling the photo conductive semiconductor GaAs in the capacitive regions of eSRR. The electric response frequency varies with the pump laser fluence, therefore, the electric response frequency is controlled to overlap with the magnetic response frequency, and the negative refractive of the metamaterials can be controlled flexibly. The extracted constitutive parameters illuminate that a bandwidth 60GHz of negative refractive is realized when eSRR and mSRR combine together (with no GaAs), while a negative band width 30GHz is realized at the same structure parameters (with GaAs) when the pump laser fluence increases to 0.4mJ/cm2. Furthermore, the transmission spectra changes from dual band to single band with the variation of pump laser fluence.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.