Three-port circulators with low symmetry based on photonic crystals and magneto-optical resonators

Abstract

Three-port circulators based on magneto-optical resonators in 2D photonic crystals with low symmetry are investigated. We consider different geometries of the circulators in photonic crystals with triangular and square unit cells. All of the three-ports possess only one specific element of symmetry named antiplane of symmetry. The theoretical part of our paper concerns scattering matrix analysis for different regimes of circulation. In particular, we define the scattering matrices of ideal circulator and a special type of conditions which allow one to transform the non-reciprocal three-port in ideal circulator. One case of non-ideal circulators is considered as well. We also discuss some peculiarities of a special regime of the circulators when they are used as isolators. Finally, one example of the circulator simulations with calculated frequency responses in photonic crystals based on triangular unit cells is presented.

THz graphene W-shaped three-port circulator with dynamical control

“…The theory of stripline and waveguide microwave circulators is well developed [2]. Circulators of different types for optical systems are also described in literature (see, for example, [3,4]). The main function of circulators is protection of a source of signal from unwanted reflections in the circuit, directing the reflected signal to the decoupled port where a matched load is connected.…”

Compact four-port circulator based on 2D photonic crystals with a 90° rotation of the light wave for photonic integrated circuits applications

“…Different genres of circulators based on PhC technology are renowned. Among them, traditional three-port Y-circulators with a triangular lattice; W and T circulators with a square lattice are familiar and have been reported [14][15][16].…”

“…Dmitriev et al reported a W-shape three-port circulator, which does not possess a rotational symmetry [15]. In 2015, the same authors reported a low symmetry three-port circulator based on magneto optic resonators, and also the different geometries of circulators and their scattering matrix [20].…”

THz dynamically controllable graphene Y-circulator

“…1 Optical circulators have been also discussed in literature. 2,[6][7][8] In THz region, one of the promising tendencies is graphene technology which allows one, in particular, to construct nonreciprocal devices. Recently, an interesting idea of an edge-guided graphene circulator was suggested in.…”