AbstractIn this paper, we propose a heterostructure multichannel add/drop filter based on 2-D photonic crystal ring-resonator in which, add and drop operations are accomplished by coupling between two W1 waveguides. The wavelength spacing of 10.3 nm, as well as the average cross-talk of −37.5 dB, are the other features of the proposed filter. Furthermore, nanoscale effects on the filter's performance including wavelength spacing, cross-talk amount, and dynamic response are considered. By taking into account these effects, the minimum wavelength spacing of 12 nm is obtained, whereas the filter’s cross-talk has an average of −40 dB. Simulations are performed using 2-D finite-difference time-domain calculations. تفاصيل المقالة

AbstractIn this paper, we investigate the atomic positions of single layer armchair graphene nanoribbon for two cases, with and without hydrogen-passivate edges, accurately and propose a formula which either removes the need of structural relaxation generally or decreases its time extremely (up to seven times). We also propose a general pattern (hyperbolic) for these positions. On the other hand, we show that edge effect influences several atoms near the edge not just one. These results can be used in software, which compute atomic positions and can increase their efficiency. In addition, we prove that the C–C bond distance depends on dimer number and differs in length and width directions, especially for narrow AGNRs. The maximum value of these differences is about 0.017 Å. تفاصيل المقالة