This paper presents a compact triple-band bandpass filter based on metamaterials. The miniaturization is realized by the principle of phase compensation of metamaterial. Compared with the conventional half-wavelength filter, the metamaterial filter has a small size of 10 mm×10 mm. The triple-band bandpass filter performance has been validated by the electromagnetic simulation software of high frequency structure simulator (HFSS). The results illustrate that the filter is designed with center frequencies of 2.4 GHz, 5.1 GHz and 8.8 GHz, bandwidths of about 7.9% (2.31—2.50 GHz), 7.8% (5.0—5.4 GHz) and 7.4% (8.50—9.15 GHz), respectively, and it shows good band pass characteristics.

A method is proposed and demonstrated to elongate the air working distance of near-field plasmonic lens with deep subwavelength resolution. It is done by employing surface plasmon illumination (SPI) with a high transverse wavevector and a plasmonic lens with a metal-dielectric-metal structure. Specially designed SPI source with subwavelength grating and multiple metal-dielectric films delivers the shifted spatial spectra components of mask patterns, which help to enhance plasmonic lens optical transfer ability of patterns' information even with a large air working distance. Moreover, a metal reflector serves to modulate the magnitude of the tangential and normal electric field components in the imaging region and brings the considerable improvement of imaging quality. Numerical simulations show that the maximum air working distance could reach 60 for 32 nm half-pitch resolution at 365 nm wavelength about six times that for the conventional superlens under normal illumination (NI). An approximate model of the air working distance elongation under SPI is given and agrees well with simulations.

In this letter, we propose a dual linearly polarized unit cell with 1-bit phase resolution for transmitarray application in X-band. It consists of two-layer metallic patterns connected by a metallized via-hole. One layer of the metallic pattern is a rectangular patch with two p-i-n diodes loaded in O-slot along electric field polarization direction, which is utilized as a receiver-antenna to achieve 1-bit phase tuning. The other metallic pattern is a dual linearly polarized transmitter-antenna that adopts a square ring patch with two p-i-n diodes distributed at the cross-polarization directions. The simulation results show that the designed antenna can achieve 1-bit phase tuning and linearly polarization reconfiguration at 10.5 GHz with insertion loss of about 1.1 dB. The characteristic of the designed transmitarray element is then experimentally validated by an ad-hoc waveguide simulator. The measured results agree with the simulated ones.

A plasmonic lens composed of a dielectric-filled nanoslits structure on an aluminum film is proposed and experimentally demonstrated. The slits' structure is designed with equal distance, length, and width, but filled with variant thickness SiO2 dielectric for specific phase retardations. A dual focused ion beam instrument is employed to mill the slits and deposit SiO2 into the slits. The phase modulation by SiO2-filled slits is illustrated by a double slits interference experiment. The light focusing behavior of the fabricated plasmonic lens is experimentally characterized by a scanning near-field optical microscope. Experimental results show good agreement with the simulations. (C) 2014 Society of Photo-Optical Instrumentation Engineers (SPIE).

We propose a hybrid hyperlens-superlens structure to achieve demagnifying nanolithography. It consists of a core of planar superlens and a shell of cylinder hyperlens. In the nanolithography process, the shell of the cylinder hyperlens could demagnify the mask patterns to the interior cylinder interface, and then the core of the planar superlens transmits the demagnified patterns to the planar output photoresist layer. The performance of this hybrid hyperlens-superlens structure is analyzed for different periods and spacing of mask and demagnification factors. The numerical simulation results agree well with the theory. It is demonstrated that the hybrid structure could be used as a superresolution device for plane demagnifying nanolithography. (C) 2014 Society of Photo-Optical Instrumentation Engineers (SPIE).