Two-dimensional photonic-crystal-based double switch-divider

Abstract

We propose and investigate a new multifunctional component, consisting of a T-junction of three waveguides in 2D photonic crystal with a square lattice. One waveguide is the input port, while the other two serve as output ports. This component can fulfil three functions: First, it can switch OFF the two output ports; second, our component can be used as a 3 dB divider of the input power; and third, it can switch ON any one of the two output ports. Changing the regime is achieved by a DC magnetic field that magnetizes a cylindrical ferrite resonator placed in the T-junction. We present an analysis of the scattering matrices of the component and calculated frequency characteristics in the low terahertz region. In the frequency band of about 1 GHz with a central frequency of f=98.46 GHz, the device has the following parameters: isolation of the output ports from the input port in the first regime is better than -30 dB, division of the input signal is about (-3.8±1.0) dB in the second regime, and isolation in the regime switch ON, where any one of the two output ports is higher than -15 dB and the insertion loss is lower than -2.0 dB.