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

Local field effect as a function of pulse duration

In this note we give semiclassical consideration of the role of pulse duration in observation of local field effects in the regime of optical switching. We show that the main parameter governing local field influence is the ratio of peak Rabi frequency corresponding to medium inversion and Lorentz frequency of the medium. To obtain significant local field effect, this parameter should be near unity that is valid only for long enough pulses. We also discuss the role of relaxation and pulse shape in this processes.Comment: 4 pages, 3 figure

Trapped-mode excitation in all-dielectric metamaterials with loss and gain

Non-Hermitian photonics based on combining loss and gain media within a single optical system provides a number of approaches to control and generate the flow of light. In this paper, we show that by introducing non-Hermitian perturbation into the system with loss and gain constituents, the high-quality resonances known as trapped modes can be excited without the need to change the symmetry of the unit cell geometry. To demonstrate this idea, we consider a widely used all-dielectric planar metamaterial whose unit cell consists of a pair of rectangular nanoantennas made of ordinal (with loss) and doped (with gain) silicon. Since the quality factor of the trapped-mode resonance can be controlled by changing both spatial symmetry and non-Hermiticity, varying loss and gain allows us to compensate for the influence of asymmetry and restore the quality factor of the localized mode. The results obtained suggest new ways to achieve high-quality resonances in non-Hermitian metamaterials promising for many practical applications in nanophotonics.Comment: 7 pages, 6 figure

Effect of frequency detuning on pulse propagation in one-dimensional photonic crystal with a dense resonant medium: application to optical logic

We consider propagation of light pulses detuned from the atomic resonance in a dense two-level medium and photonic structures with it. The large density of the medium is important to decrease spatial scale of such nonlinear effects as pulse compression, though it does not provide any fundamentally new phenomena as compared to dilute media. Frequency detuning decreases the effectivity of such nonlinear phenomena as pulse compression and dispersion spreading compensation as well. We propose simple logic gates based on interaction between two pulses in one-dimensional nonlinear photonic crystal. It turned out, that frequency detuning is necessary to obtain ultrafast AND gate, while OR and NOT gates can be realized in the system without detuning.Comment: 7 pages, 6 figure

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