Low-loss Y-junction two-dimensional magneto-photonic crystals circulator using a ferrite cylinder

A new defect structure of two-dimensional magnetic-photonic crystal is given and a new three-port Y-junction circulator using a ferrite cylinder is proposed in this short paper. Based on the agreements between the resonance frequency of micro-cavity constructed by a point defect in the 2D triangular lattice photonic crystal with those numerical results of corresponding literatures, external characteristics of the circulator were calculated by the plane wave expansion method and finite element method. According to the scaling theory of Maxwell's equations, a 3cm Y-junction 2D MPCs circulator is developed by scaling the radius of the center ferrite cylinder. The results show that there is a significant improvement for insertion loss 0.062dB and isolation 26.2dB compared with those in literatures. •In this manuscript, several aspects of this study would make it interesting to not alone general readers of Optics Communications, but also especially to the researchers who concentrate on photonic crystals, magneto-optics systems, photonic crystal waveguides, optical circulator and so on.•First in this manuscript, a new defect structure of two-dimensional magnetic-photonic crystal is given and a new three-port Y-junction circulator using a ferrite cylinder is proposed. Based on the scaling theory of Maxwell’s equations, a 3cm Y-junction 2D MPCs circulator is developed by scaling the radius of the center ferrite cylinder at last.•Due to the structures are compact and extremely low loss, they are appealing and quite novel for further application and manufacturing. For details you may check inside of the manuscript.•In brief, this new circulator have perfect operating properties as follows: (1) structure is relatively simple, the process is easy to implement; (2) only one ferrite cylinder in the center, act as resonant cavity and also provide Faraday rotation, greatly reducing the insertion loss, low up to 0.0037dB; (3) broadband, isolation is greater than 10dB and insertion loss is less than 0.5dB in a wide frequency range; (4) circulator can be obtained in different operating frequencies by flexibly changing the radius of the center ferrite cylinder in the photonic band gap.•Consequently, it may have great potential for applications in large-scale optical integrated circuits.