Abstract
An all optical comparator is designed based on photonic crystals. The proposed structure was designed based on optical threshold switching that is realized using three nonlinear ring resonators. All nonlinear rings have the same optical characteristics, such that they can drop low intensity (as low as 0.5 W/μm2) optical waves at 1550 nm, but cannot drop the optical waves with optical intensity of 1 W/μm2. For the proposed structure the rise and fall time are about 2 and 1 ps, respectively. Therefore the bit rate is about 167 GHz and the ON/OFF contrast ratios for O1, O2, and O3 are 13.5, 13.6, and 13.3 dB, respectively.
Self-phase modulation (SPM) induces a varying refractive index of the medium due to the optical Kerr effect. The optical waves propagation (OWP) in a medium with SPM occupied a remarkable area of research in the literature. A model equation to describe OWP in the absence of SPM was proposed very recently by Biswas–Arshed equation (BAE). This work is based on constructing the solutions that describe the waves which arise from soliton-periodic wave collisions. A variety of geometric optical wave structures are observed. Here, a transformation that allows to investigate the multi-geometric structures of OW’s result from soliton-periodic wave collisions is introduced. Chirped, conoidal, breathers, diamond and W-shaped optical waves are shown to propagate in the medium in the absence of SPM. The exact solutions of BAE are obtained by using the unified method, which was presented recently. We mention that the results found here, are completely new.
Energy and wave-action flows underlying Rayleigh-Jeans thermalization of optical waves propagating in a multimode fiber
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