A new design of a 4-channel optical demultiplexer based on photonic crystal ring resonator using a modified Y-branch

In this paper, we propose a new structure to design a 4-channel optical demultiplexer using a modified Y-branch structure with 4 hexagonal photonic crystal ring resonators. A new optical filter with a high transfer coefficient and quality factor has been introduced and designed in the present paper using a hexagonal photonic crystal ring resonator, which has then been used to design a 4-channel optical demultiplexer. The proposed demultiplexer has an average transfer coefficient of 95.5% and a high quality factor of 4164.6. It also has a channel spacing of 2.75 nm and a spectral width of 0.4 nm. The maximum and minimum crosstalk values of the channels are –10.5 and –36.5 dB, respectively. To study the photonic band structure, the plane wave expansion method has been used and the finite-difference time-domain method has also been used to analyze the optical behavior of the structure.