Optical Transmission Characteristics Of Slotted Silicon Photonic Crystal Waveguide

Photonic crystal(PhC)is an artificial new structure,its structure is characterized by its periodic distribution of refractive index,the photonic band gap is the most prominent feature of photonic crystals,light with frequency in the band gap cannot be transmitted in it,based on this characteristic,many new methods for controlling light wave transmission using photonic crystal structures have been proposed,and many photonic crystal devices have also been born,such as photonic crystal waveguides,photonic crystal fibers,and so on are common to see.Among them,photonic crystal waveguide(PCW)is the focus of this paper,it can be obtained by introducing line defects into the complete structure,the line defects will destroy the periodic characteristics of the photonic crystal,so that the light waves originally in the photonic band gap can transfer in the defect location.If a slotted channel is introduced at the line defect position,a slot photonic crystal waveguide can be obtained,and the light wave in the photonic band gap can be transmitted in the low refractive index slot.Silicon materials have good development prospects in integrated optics because of their high refractive index,excellent nonlinear characteristics,and compatibility with CMOS processes.Based on silicon material,a silicon photonic crystal slot waveguide is designed by combining photonic crystal waveguide and ordinary slot waveguide,and its transmission characteristics are studied.The main contents of this paper are as follows:1.Analyze the band structure of the complete photonic crystal slab and choose the appropriate structural parameters.The band structure of the photonic crystal slab was calculated based on the plane wave expansion method using the BandSOLVE simulator of RSOFT software.According to the band structure,the lattice type,slabhight and pore size of the photonic crystal are selected to determine the appropriate structural parameters.The final parameters are: the lattice type is triangular lattice,the thickness of the plate is 0.6a,the air hole radius is 0.43 a,and the analysis mode is even mode.2.Introduce defects and analyze defect patterns.After determining the parameters of the complete photonic crystal plate,first remove a row of air holes to form a line defect waveguide,and then introduce a groove channel at the line defect position to form a groove waveguide.By using the fullzone analysis method for the defect waveguide,the defect mode structure and field distribution of the waveguide are obtained.Then change the structural parameters of the defect location and nearby location,observe the structural changes of the defect mode and the change of the field distribution,and briefly analyze the slow light effect.3.Transfer simulation.The transmission of the 1550 nm signal light in the line defect waveguide and the slot defect waveguide is simulated based on the finite difference time domain method.