Transmission characteristics of Y‐type optical distributor in triangular lattice photonic crystals with Al2O3 rods

Abstract

AbstractIn this work, a Y‐type optical distributor formed by triangular lattice photonic crystals is numerically and experimentally investigated. The crystals are formed by cylindrical Al2O3 rods array in the air. The band gaps of TE modes for the photonic crystals are calculated by plane wave expansion method. Three photonic band gaps appear numerically within the normalized frequency range 0∼0.8 in the triangular lattice photonic crystals. Based on a Y‐type defect structure, an equal optical distributor is realized within the first photonic band gap of 0.2380 ∼0.2823 . The transmission characteristic of the distributor is calculated by finite element method. To validate the numerical results, experiments were performed in the microwave regime. An Agilent E8361C vector network analyzer was used. The measured reflection and transmission characteristics of the photonic crystals sample agree with the numerical results between 9.77 and 9.91 GHz in the first photonic band gap. At the frequency of 9.86 GHz, the isolation of the photonic crystals reaches −39.02 dB and about 95.72% energy reflecting back to the input port. Furthermore, the equal optical distributor is also validated by making a comparison between the numerical and experimental results.