Transparent conducting device for electromagnetic waves (Vol. 45 No.4)
It is highly desirable to make a metal transparent for electromagnetic waves, owing to many application requests for transparent metals in optoelectronics devices. However, it is well known that a high-conducting metal with a high electron density is generally opaque for electromagnetic waves, since the metal’s permittivity is generally very negative at optical frequencies. Here, a freestanding transparent conducting device based on multilayer metamaterials is theoretically demonstrated at terahertz frequencies. It is realized by depositing periodic metallic patches on top and bottom of the subwavelength metallic mesh. The high transmission of the designed system is attributed to the impedance matching to the vacuum. This design of a transparent conducting device opens a high transmission window within the technologically relevant THz frequency range. This device may find plenty of applications in optoelectronic electrodes, micro-electronic displays, and the miniaturization and integration of THz components, where both high electrical conductivity and high optical transmission are desirable.
Z. Song, Z. Gao, Y. Zhang and B. Zhang, “Terahertz transparency of optically opaque metallic films”, EPL, 106, 27005 (2014)