Tunable All-optical Wavelengths Based On PPLN Waveguide Sum Frequency And Difference Frequency Conversion

The importance of AOWC(All Optical Wavelength Converter)in the future WDM(Wavelength Division Multiplexing)optical transport network key technology will be introduced in this paper.AOWC can realize the conversion of the optical signal between the two different wavelengths in the light domain,without speed limit of the traditional optical / electrical / optical wavelength converter.AOWC has the extensively potential application and commercial value in many fields,such as network Interconnection,optical switch,optical cross-connect,wavelength routing and wavelength reuse.Compared to several common AOWC techniques,the AOWC of cascaded second-order nonlinear effects based on periodic polarization inversion of lithium niobate(PPLN: Periodically Poled LiNbO3)has many advantages.Based on this,the main research of this paper are as follows:The allowable range of the wave-vector mismatch of the frequency-difference and difference-frequency process and the frequency-multiplication and difference-frequency processes is calculated respectively,and the wave loss in the two processes is compared under the condition that the wavelength variation of the pump light is equal.And the transient coupling equation of all-optical wavelength conversion with frequency and difference frequency cascade are presented in this paper.Through numerical simulation,the three-dimensional signals of signal light,pump light,control light,and frequency light and converted light are obtained.In order to improve the tunability and flexibility of the wavelength converter,this paper presents an all-optical wavelength conversion scheme based on PPLN waveguide and SFG + DFG second-order nonlinear process.The scheme can realize the conversion from the signal light of any wavelength to the output light of any wavelength.,and the signal light information is converted to the converted light.And in order to obtain the flat broadband wavelength conversion characteristic,this paper first uses the step segment grating structure to change the PPLN waveguide parameters,and studies the wavelength conversion process based on the SFG + DFG effect.The results show that the conversion bandwidth and the conversion efficiency are calculated and analyzed.From the results of this study,The all-optical wavelength conversion tunable transform based on the second-order nonlinear process,and the better quality of signal is obtained.The step segment grating structure is used to study the wavelength conversion,and a relatively high conversion efficiency and flatness are obtained.Therefore,the research of this topic is of great significance in the study of all-optical wavelength conversion.