Design And Performance Analysis On Compound Lattice Photonic Crystal Infrared Fiber

With the rapid development of optical communication technology, the infrared optical fiber is widely used in industrial, medical, military and many other fields. However, the weaknesses of the present infrared optical fiber limit its usage, such as the using of toxic materials, small band gap and large transmission loss.Therefore, the exploration of a non-toxic infrared optical fiber with a large band gap and a low transmission loss will be of great significance.A novel infrared photonic crystal fiber(PCF) with compound triangular lattice structure is proposed in this paper. Using a new arsenic-free eco-friendly material of Ge30Sb8Se62 chalcogenide glass as substrate, the infrared PCF has a cladding structure composed of nested circle and square cylinders.In order to optimize the structure parameters of infrared PCF based on compound lattice, the band gap and loss characteristics can be analyzed by plane wave expansion method and full vector finite element method.The simulation results show that the device has an optimal performance with a band gap of 0.523 and a leakage loss of 0.581dB/km when the duty ratio d/ a ?0.75, lattice constant a=8.37μm and the number of the cladding layers n=10.Due to the inevitable defects introduced in the infrared PCF based on compound lattice during the practical fabrication process, the influence of some common defects on the characteristics of PCF can be investigated. It is shown that the loss first increases, and then decreases periodically with the deformation increase of air cylinders. The closer the air cylinder defect is to the fiber core, the greater the fluence on the loss characteristics. In addition, the corresponding loss increases then decreases with a whole row of air cylinders dislocation, and the loss becomes larger when the dislocation value ranges from 0.3a to 0.7a. It is provided that the results have reference and practical value for the fabrication of infrared PCF with compound lattice structure.The infrared PCF with compound lattice structure presented in this paper combines many advantages, such as large band gap, low loss, high mechanical strength, good infrared permeability, non-toxic, high performance of transmission, and so on. It improves the performance of infrared fiber and has widespread applications in the field of medical and industrial.