Transmission enhancement in loss-gain multilayers by resonant suppression of reflection

Using the transfer-matrix approach and solving time-domain differential equations, we analyze the loss compensation mechanism in multilayer systems composed of an absorbing transparent conductive oxide and dielectric doped with an active material. We reveal also another regime with the possibility of enhanced transmission with suppressed reflection originating from the resonant properties of the multilayers. For obliquely incident and evanescent waves, such enhanced transmission under suppressed reflection turns into the reflectionless regime, which is similar to that observed in the PT-symmetric structures, but does not require PT symmetry. We infer that the reflectionless transmission is due to the full loss compensation at the resonant wavelengths of the multilayers.Comment: 12 pages, 10 figure

Pseudocanalization regime for magnetic dark-field hyperlens

Hyperbolic metamaterials (HMMs) are the cornerstone of the hyperlens, which brings the superresolution effect from the near-field to the far-field zone. For effective application of the hyperlens it should operate in so-called canalization regime, when the phase advancement of the propagating fields is maximally supressed, and thus field broadening is minimized. For conventional hyperlenses it is relatively straightforward to achieve canalization by tuning the anisotropic permittivity tensor. However, for a dark-field hyperlens designed to image weak scatterers by filtering out background radiation (dark-field regime) this approach is not viable, because design requirements for such filtering and elimination of phase advancement i.e. canalization, are mutually exclusive. Here we propose the use of magnetic ($\mu$-positive and negative) HMMs to achieve phase cancellation at the output equivalent to the performance of a HMM in the canalized regime. The proposed structure offers additional flexibility over simple HMMs in tuning light propagation. We show that in this ``pseudocanalizing'' configuration quality of an image is comparable to a conventional hyperlens, while the desired filtering of the incident illumination associated with the dark-field hyperlens is preserved

Asymmetric transmission in planar chiral split-ring metamaterials: Microscopic Lorentz-theory approach

The electronic Lorentz theory is employed to explain the optical properties of planar split-ring metamaterials. Starting from the dynamics of individual free carriers, the electromagnetic response of an individual split-ring meta-atom is determined, and the effective permittivity tensor of the metamaterial is calculated for normal incidence of light. Whenever the split ring lacks in-plane mirror symmetry, the corresponding permittivity tensor has a crystallographic structure of an elliptically dichroic medium, and the metamaterial exhibits optical properties of planar chiral structures. Its transmission spectra are different for right-handed versus left-handed circular polarization of the incident wave, so the structure changes its transmittance when the direction of incidence is reversed. The magnitude of this change is shown to be related to the geometric parameters of the split ring. The proposed approach can be generalized to a wide variety of metal-dielectric metamaterial geometries

Magnetic field concentration with coaxial silicon nanocylinders in the optical spectral range

Resonant magnetic energy accumulation is theoretically investigated in the optical and near-infrared regions. It is demonstrated that the silicon nanocylinders with and without coaxial through holes can be used for the control and manipulation of optical magnetic fields, providing up to 26-fold enhancement of these fields for the considered system. Magnetic field distributions and dependence on the parameters of nanocylinders are revealed at the wavelengths of magnetic dipole and quadrupole resonances responsible for the enhancement. The obtained results can be applied, for example, to designing nanoantennas for the detection of atoms with magnetic optical transitions

Semangat ekonomi pesantren salaf: telaah sosiologis terhadap perekonomian Pondok Pesantren Sidogiri

Beberapa persoalan yang dikaji dalam skripsi ini (1) Bagaimana bentuk konkrit spirit kapitalisme dalam pesantren salaf? (2) Apa yang memotifasi sidogiri bergerak da1atn bidang ekonomi? (3) Kenapa semangat kapitalisme terjadi pada lembaga salafiah? Adapun tujuan penelitian ini yang pertama, mendapat kebenaran tentang pengaruh teks suci terhadap perilaku ekonomi, yang kedua mengetahui sejauh mana nilai-nilai teks membentuk perilaku ekonomi dan yang terakhir menjelaskan peran ekonomi pesantren dalam menopang kehidupan pesantren. Dengan pisau analisa action theory Weber, diharpakan mampu memberikan suatu kesimpulan yang utuh tentang gejala sosial di atas. Teori tindakan digunakan oleh Weber sebagai kerangka konsepstual untuk memahami kenyataan dalam masyarakat. Weber beranggapan bahwa yang benar-benar riil dalam masyarakat adalah individu. Bagaimana hal ini bisa paradoks, satu sisi subyek kajiannya adalah lembaga namun pada sisi yang lain subyek analisanya adalah individu?. Melalui proses yang panjang dibagian akhir telah desebutkan bahwa spirit ekonomi kapitalisme pesantren salaf bukan representasi dari ekonomi sistem dunia, hal ini karena etika ekonomi Sidogiri tetap berpijak pada teks suci sebagai landasan berpikir dan bertindaknya. Artinya teks menjadi pedoman dasar dalam menata perekonomian Pesantren