Supercontinuum Generation In Chalcogenide And The Application In All-optical Quantization

Analog-to-digital converter(ADC)is the bridge between the digital world and the analog world.It is the key front-end devices of the broadband digital system.With the rapid development of the digital system,electronic ADC is facing challenge and test.In order to solve the inherent electronic bottleneck problem of electronic technology fundamentally,all-optics ADC is proposed to convert the analog signals to digital ones by photonic technologies,which can realize properties such as large bandwidth,high rate.There are many problems in the existing ADC scheme,such as the realization of high quantization resolution in broadband condition,integration,miniaturization,low power consumption and so on.All-optical ADC mainly includes three parts,sampling,quantization and coding.All-optical sampling of analog signals has been fully researched in the past few decades.As the key part of all-optical ADC,the implementation technology all-optical quantization remains to be improved.In this paper,aiming at the existing problems in all-optical quantization,novel slot waveguide structure combined with chalcogenide material which has excellent nonlinear characteristicsis used to research the generation of supercontinuum(SC)and its application in all-optical quantization.The third order nonlinear optical effects,the integration of all-optical quantization system,high-performance all-optical quantization methods are in deeply researched.The main content of the research and the main innovative achievements are summarized as follows:1.The important position of all-optical ADC in digital communication system are introduced.The research status and development history of all-optical quantization is reviewed in our paper.Several kinds of all-optical quantization are introduced in this paper.2.Nonlinear schrodinger equation(NLSE)which can describe the evolution characteristics of optical pulse in a nonlinear medium is derived and two kinds of numerical solution method of NLSE are introduced.The influence of dispersion and nonlinearity on the pulse transmission characteristic is discussed.The inherent quantitative error and calculation methods is introduced.3.The influence of slot waveguide geometry construction on dispersion and nonlinearity is analyzed.Then,slot waveguide is optimized based on the result for SC generation.The mechanism of realization of all-optical quantization with SC is introduced and numerical simulation of the proposed scheme is implemented.In our simulation,the low input peak power of 900 mW is used to achieve the 4-bit quantization resolution with the ENOB of 3.98-bit.At the same time,the length of the proposed waveguide is only 1.5 cm.At the same time,the performance of proposed quantizer is analyzed in our paper.4.Due to the better effect of short pulse in all-optical quantization,slot waveguide with variable widthis designed for pulse compression.The slot waveguide with effective mode field area of 0.1?m2and large nonlinear coefficient of 160 W-1m-1 can be obtained.The input pulse peak power of 7.6 W is enough for soliton-self compression.The input pulse is compressed from 1.5 ps to 14.78 fs in a 1.4 cm-long waveguide,andthe pulse compression factorof more than 100 times is achieved.The novel slot waveguide structure combine with chalcogenide which has good nonlinear properties is applied in this paper.The nonlinear characteristics of the proposed waveguide is studied theoretically and the application in quantization is explored.It will provide theoretical research foundationfor the implementation of integration,high performance,low power consumption all-optical quantization scheme.