Research On Photonic Crystal Electro-Optic Modulator Chip Based On LNOI

The rapid development of information technology has raised the standards for the data transmission rate,bandwidth and anti-interference ability,which rendering traditional ridge-wave conductive optical modulator no longer satisfactory.As a new type of artificial microstructure material,photonic crystal has unique bandgap and slow light characteristics that can fundamentally solve the problem of light control of Micro-Nano optoelectronic devices,and provides a new way of achieving the ultra-intensive,high-speed,high-bandwidth requirements of integrated photonic devices.This thesis has focused on the research of photonic crystal electro-optic modulation chip based on Lithium Niobate Thin Film,analyzing the photonic crystal band gap structure,designing the photonic crystal waveguide,and has completed the electro-optic modulation chip design based on the photonic crystal film.The thesis has important academic research value and significance of practical engineering application.The main research work of this thesis includes:(1)Analyzing the current research and development status of optoelectronic systems,photonic crystals and electro-optic modulators within the country and abroad,and proposing the research ides of this thesis;(2)Analyzing the physical characteristics of photonic band gap,photonic localization and slow light effect and designing photonic crystal calculation model of band gap structure,based on the theory of photonic crystals;(3)Implementing the bandgap scan of the four photonic crystals based on the plane wave expansion method and the finite time domain difference method,while the bandgap pattern of each structure is deeply analyzed and five kinds of two-dimensional photonic crystal structures with excellent bandgap performance are designed;(4)Designing and optimizing the triangular lattice photonic crystal curved waveguide and the straight waveguide,in which the transmission efficiency of the air column and the lithium niobate column waveguide based on the triangular lattice reached 97.6% and 99.2 %respectively,based on the structure of the MZI electro-optic modulator;(5)Analyzing the preparation process of the lithium niobate thin film(LNOI)in detail,and having completed the design of the photonic crystal electro-optic modulator based on the LNOI on-chip air column structure by using optimized photonic crystal curved waveguides and straight waveguides,while having conducted five kinds of modulation bandwidth calculations on the electro-optical modulation chip of this structure,with the design requirement met by performance indicators.In this paper,a photonic crystal electro-optic modulation chip based on LNOI is designed.The modulator chip can achieve a modulation bandwidth of 150 GHz for the1550 nm communication band.Moreover,the half-wave voltage is only 1.78 V and the device length is only 80.7?m.Its performance is far superior to the traditional ridge-wave conductive optical modulator,while the size of the device is greatly reduced.The research results of the paper provide new design methods and ideas for the future research of ultra-high and ultra-wide modulation bandwidth integrated electro-optic modulators,which have important academic research value and engineering significance.