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Non-reciprocity using quadrature-phase time-varying slab resonators
, Article Journal of the Optical Society of America B: Optical Physics ; Volume 37, Issue 1 , 2020 , Pages 88-97 ; Memarian, M ; Mehrany, K ; Sharif University of Technology
OSA - The Optical Society
2020
Abstract
In this paper, it is shown that non-reciprocity can be observed in time-varying media without employing spatiotemporal modulated permittivities. We show that by using only two one-dimensional Fabry–Perot slabs with time-periodic permittivities having quadrature-phase difference, it is possible to achieve considerable non-reciprocity in transmission at the incidence frequency. To analyze such a scenario, generalized transfer matrices are introduced to find the wave amplitudes of all harmonics in all space. The results are verified by in-house finite-difference time-domain simulations. Moreover, in order to have a simple model of such time-varying slab resonators, a time-perturbed coupled-mode...
Wide-band/angle blazed dual mode metallic groove gratings
, Article IEEE Transactions on Antennas and Propagation ; 16 June , 2020 ; Abbassi, M. A ; Rahmani, B ; Memarian, M ; Mehrany, K ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2020
Abstract
A simple approach to acquire wide-band/angle blazing operation in one-dimensional metallic gratings is investigated by means of mode-matching and equivalent circuit analysis. The gratings are single-groove perfectly conducting gratings that support two propagating guided modes (opposed to typical single mode cases). It is shown under what conditions, one can achieve blazing over a wide range of frequencies and angles. Most importantly, it is identified what governs blazing, in particular the true matching condition that needs to be satisfied, and how the structures’ multiple resonances play role in achieving such matching and tailoring the bandwidth. Parameters of the proposed equivalent...
Wide-band/angle blazed dual-mode metallic groove gratings
, Article IEEE Transactions on Antennas and Propagation ; Volume 69, Issue 1 , 2021 , Pages 379-386 ; 0018926X (ISSN) ; Abbassi, M. A ; Rahmani, B ; Memarian, M ; Mehrany, K ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2021
Abstract
A simple approach to acquire wide-band/angle blazing operation in 1-D metallic gratings is investigated by means of mode-matching and equivalent circuit analysis. The gratings are single-groove perfectly conducting gratings that support two propagating guided modes (opposed to typical single-mode cases). It is shown under what conditions one can achieve blazing over a wide range of frequencies and angles. Most importantly, it is identified what governs blazing, in particular the true matching condition that needs to be satisfied, and how the structures' multiple resonances play role in achieving such matching and tailoring the bandwidth. Parameters of the proposed equivalent circuit model...