1-D Photonic Crystal Nanobeam Cavity With Large Free Spectral Rangre Design And Application Research

With the development of a series of new technologies such as mobile Internet,cloud computing,big data and artificial intelligence,human society has ushered in a new revolution in information technology.Newer communication systems,such as 5G systems,are pursuing higher user experience rates,greater bandwidth,and lower energy costs.Under these circumstances,integrated circuits and semiconductor devices,which have brought great changes to human life in the past,have failed to meet the needs of the development of modern society.The development of electronic technologies and integrated circuits has encountered bottlenecks.Therefore,people have proposed the use of photonic integrated circuits to replace electronic integrated circuits to achieve information transmission,processing and storage.With the development of nanotechnology and silicon processing technology,photonic crystals based on silicon-based materials become an ideal material for realizing photonic integrated circuits.A variety of different functions of photonic crystal optical devices are continuously put forward,among them,one-dimensional photonic crystal nanobeam cavities(1D-PCNC),which have high Q value,ultralow mode volume,ultracompact size,high degree of integration and its inherent advantages are easily coupled to waveguides,have great advantages in enhancing the interaction of light and matter.And compared to the two-dimensional photonic crystal platforms,1D-PCNCs have a smaller size,are easily to manufacture,also have greater advantages in integrated multiplexing,which attracted more and more researchers' interest.In this paper,1D-PCNC is mainly studied using three-dimensional finite-difference time-domain(3D-FDTD),which focus on the problem of the free spectral range of 1D-PCNC is too narrow to apply to ultra-compact integrated multiplexing.A new method for improving the performance parameters of 1D-PCNC(Including Q Value and FSR)is proposed.On this basis,we further analyze the realization and application of 1D-PCNC with ultralarge FSR in on-chip dense sensing multiplexing and DWDM,specifically include the following:1)Design and performance analysis of 1D-PCNC with Large FSR.The new method of increasing the Q value and FSR is studied in detail.Using the method of 3D-FDTD,the results show that the Q>105,FSR=197nm,and compared to the current type of 1D-PCNC,the FSR increased by an order of magnitude,and the structure is simple and flexible,which laid a solid foundation for the ultracompact on-chip integrated sensing multiplexing and DWDM.2)Research and performance analysis of on-chip optical power splitter and sensor array based on 1D-PCNC.Using the method of 3D-FDTD,the results show that the EL=1.38dB and UNIF=0.62dB.Compared to the known optical power splitters,the structure is more simple and flexible.The size is only 15um*40um*0.22um.On this basis,the sensor array based on 1D-PCNC is designed.The results show that the refractive index sensitivity are S1=170.6nm/RIU,S2=152.7nm/RIU,S3=138.5nm/RIU,S4=128.1nm/RIU,S5=120.5nm/RIU,the size of the whole structure is only 7um*65um,compared to the previous sensor array structure based on two-dimensional photonic crystal platforms,the size is reduced by three orders of magnitude,while the refractive index sensitivity and Q value have no effect,therefore,this research will provide strong reference for the future research and application in the field of sensor multiplexing integrated.3)Research and performance analysis of DWDM based on one-dimensional photonic crystal nanobeam cavity.Using the method of 3D-FDTD,the results show that the average channel spacing of this structure is 115GHz(?0.7nm),the size of a single demultiplexing channel is 22.5um2.Compared to the two-dimensional photonic crystal platforms,the size is reduced by 5 times,the channel spacing is reduced by 2 times,and the channel crosstalk is fundamentally suppressed by increasing the Q value of the cavity.On this basis,the 100-channel DWDM function can be achieved by further theoretical analysis,the average channel spacing is100GHz,which provides a strong reference for the the research and application based one-dimensional photonic crystal nanobeam cavity structure in DWDM system in future.