Enhanced transmission in rolled-up hyperlenses utilizing Fabry-Pérot resonances

Abstract

We experimentally demonstrate that the transmission though rolled-up metal/semiconductor hyperlenses can be enhanced at desired frequencies utilizing Fabry-Pérot resonances. By means of finite difference time domain simulations we prove that hyperlensing occurs at frequencies of high transmission.Metamaterials offer the possibility to tailor their effective optical parameters 1,2 allowing e.g. sub-wavelength imaging. Beside metamaterials with negative index of refraction 3-5 , metamaterials consisting of alternating layers of metal and dielectric 6,7 are able to transmit electromagnetic waves containing sub-wavelength details of an object. In the latter case sub-wavelength imaging relies on the anisotropic permittivity of the multilayer structure leading to unidirectional propagation of electromagnetic waves. Magnification of a sub-wavelength object can be achieved if the multilayers are curved 8 . As a consequence the light is channeled in radial direction. These so called hyperlenses have been fabricated consisting of multilayers of Ag and oxides with an effective plasma frequency in the violet and ultraviolet regime 9,10 . They are most efficient close to the effective plasma frequency in the longitudinal component of the permittivity of the metamaterial 6 , which can be tuned by the ratio of the thicknesses of the dielectric and metal layer. Recently we have shown that using the concept of selfrolling strained layers 11-14 , one can fabricate a rolledup metal/semiconductor microtube which exhibits optical anisotropy and acts as a hyperlens 15 . The operation frequency of these rolled-up hyperlenses (RHLs) is tunable in the visible and near-infrared regime.In this letter we propose a concept to optimize the transmission through a metamaterial. We utilize FabryPérot resonances related to the total thickness of the metamaterial to obtain increased transmission in a desired frequency regime. We illustrate this concept for the example of a RHL 15-18 consisting of alternating layers of Ag and semiconductor as sketched in Fig. 1(a). We show that the number of rotations of our RHL can be used to maximize the transmission at their operation frequency and obtain values as high as 52 %. Finite difference time domain (FDTD) simulations prove the hyperlensing ability of the presented structures.The preparation of the RHLs is described in the following: Initially a semiconductor heterostructure is grown on a GaAs substrate using molecular beam epitaxy. The heterostructure consists of a GaAs buffer

Hyperlenses and metalenses for far-field super-resolution imaging

“…Although the intrinsic metal loss is unavoidable, the hyperlens can be optimized by increasing the amount of the dielectric component or working at longer wavelengths. A higher optical transmission can also be realized with resonant structures 40,41 . Moreover, instead of conformal film deposition, fabrication based on rolled-up technology provides an alternative method for controlling film conformality and roughness [41][42][43][44] .…”

Exceptional transport property in a rolled-up germanium tube

“…Advanced concepts in inorganic semiconductor nanomembrane (NM) science and technology lead foundations for emerging classes of three-dimensional tubular nano/ micro-architectonics. [1][2][3] These tubular architectures, realized by a rolled-up technique, are of interest due to their widely innovative applications in energy storage, 4 robotics, 5,6 electronics/phonics, [7][8][9][10][11][12] and optoelectronics. 13 With elaborate designs of geometry or surface chemistry during the rolling up process, the corresponding physical properties and device performances can be artificially tuned.…”

Extreme stiffness hyperbolic elastic metamaterial for total transmission subwavelength imaging

“…On the other hand, several studies to enhance the transmission through the lenses have been reported. Higher optical transmission was realized with the Fabry-Perot resonance mechanisms 25 26 27 and the radius-dependent permeability for an impedance-matched condition 28 . In the acoustic counterpart, the zero-mass effect has been implemented 29 30 31 to overcome the thickness limitation rising from resonance based lens 32 33 which restricts the device’s thickness to be chosen depending on the operating frequency.…”