Study On Electro-optic Modulator Based On Photonic Crystal AAH Resonator

With the evolution of information technology,larger capacity and higher speed of information transmission is needed.Among the existing information media,light is the most ideal one.Optical network greatly satisfy the requirements for high-speed and high-efficiency of information transmission.As one of the most important devices in optical networks,opto-electronic modulators have being attracted a wide attention.This kind of device controls the modulation and transmission of optical signal using electrical effect.It realizes the transformation of communication medium from electricity to light,and greatly promotes the development of all-optical network.In recent years,integrated optics has become the development trend in the field of opto-electronic devices.Photonic crystal based opto-electronic modulators have many advantages,such as low loss,high extinction ratio,low power consumption,compact and easy integration.It has an important application value to study photonic crystal based opto-electronic modulators.In this paper,the theory of carrier dispersion effect and the theoretical model of Aubry-Andr(?)-Harper(AAH)are studied.Based on this,a model of photonic crystal opto-electronic modulator based on AAH resonator is proposed.A circular air hole is etched on the base plate to form a triangular lattice photonic crystal structure,an AAH cavity is introduced at the line defect of the two-dimensional photonic crystal,and a p-n junction is formed by doping the line defect waveguide.In order to study the structural characteristics of AAH resonator,three resonator modulators with different lattice mismatch are designed.These three devices all utilize the effect of defect-mode shifting to realize optical modulation.FDTD Solution module and Device module of Lumerical simulation software are used to simulate its optical and electrical parameters,respectively,The structural parameters of the devices are optimized,and the influences of the parameter variation are studied.The performances of three modulators with different lattice mismatch are compared and analyzed.According to the simulation results,when the lattice mismatch constant is ?=8898.0,the device achieves the best performances.The length of the device is 9.03 ?m,the 3 dB bandwidth is 1.01 nm,and the refractive index difference is 0.01.The narrow bandwidth modulation of transverse electric(TE)mode with wavelength of 1550 nm can be realized,the insertion loss of which is 1.19 dB and the extinction ratio is 29.89 dB.The influence of energy is small.The proposed photonic crystal modulator based on AAH resonator has small size,easy integration andhigh extinction ratio,which is of great significance for silicon photonic integrated devices.