Research On The Slow Light Characteristics Of Liquid-filled Photonic Crystal Waveguides

Slow light can enhance the interaction between light and matter,which is the key to realize optical buffer and "all optical network" communication.So,the research on slow light waveguide of photonic crystal is of great meaning and application value.Under this background,based on the 2-D triangular lattice elliptical hole photonic crystal,this paper breaks the periodicity of photonic crystal by introducing a line defect to form the waveguide and optimizes the group index and bandwidth of slow light in the allowable dispersion range.Firstly,this paper introduces the concepts of photonic crystal,the principle of slow light waveguide transmission and calculates the band gap of photonic crystals using the plane wave expansion method,all these lay the theoretical foundation for the following simulations.Secondly,2-D triangular lattice elliptical holes slotted photonic crystal waveguide is taken as the research object,because the elliptical hole which is the simplest and the most suitable for fabrication of noncircular hole has more adjusting degree than the circle hole.It is shown that the transmission efficiency of the elliptical holes photonic crystal waveguide is 16%higher than that of the circular holes.By optimizing the size of the elliptical holes,the normalized delay bandwidth product of the slow light can reach up to 0.425.In addition,in order to realize the dynamic adjustment and optimization of slow light at any time,the liquid infiltrated post processing technology is used in this text to analyze the effect of different infiltrated liquid in the first row elliptical holes near the line defect on the slow light.A liquid infiltrated asymmetric waveguide is introduced,it is found that compared with symmetric waveguide,the group velocity dispersion of slow light obtained in asymmetric waveguides can be reduced.Finally,a Slot waveguide is added to the elliptical holes photonic crystal,because the photonic crystal Slot waveguide can limit the energy of light in the air Slot region,which can further enhance the interaction of light and matter.In order to increase the scope and flexibility of the adjustment,this text infiltrates different refractive index liquid in the first and second rows of elliptical holes near the line defect,and by fine-tuning the refractive index of the liquids,the group refractive index of slow light is changed from 33.3 to 247,the bandwidth is changed from 12.6nm to 1.2nm.And it is also proved that the unavoidable manufacturing errors in practice can be compensated by adjusting the refractive index of the liquids.