Research On Cost-Effective All-Optical Wavelength Conversion

With the rapid development of the Internet,mobile Internet and the Internet of things,the number of optical fiber broadband subscribers and broadband access speeds are surging upwards,which make all-optical network construction face a huge challenge.In order to meet the development trend of technology and the new business needs of users,it is an urgent problem to be solved by reducing system cost and complexity,increasing spectrum efficiency,and expanding network capacity to improve system performance.All-optical wavelength conversion,as a key technology in all-optical networks,introduces discrete multi-tone signals and twin single-sideband modulation to improve signal spectrum utilization and system capacity.In this thesis,the external modulation technology is used to study the transmission performance of the all-optical wavelength conversion system.The theoretical derivation and system simulation are carried out around the all-optical wavelength conversion system with high performance.The main achievements are as follows:(1)The effect of high-order sideband suppression ratio of the all-optical wavelength conversion system based on polarization-multiplexed signals with carrier suppression parallel-pump has been analyzed.By controlling the modulation depth of the modulator within a certain range,the converted signal corresponding to the high-order sideband suppression ratio can be directly received without crosstalk of the polarization-insensitive signal,and the filtering step of filtering the residual sideband can be omitted to reduce the complexity and cost of the system.(2)The influence of single-sideband modulated signal on the performance of all-optical wavelength conversion system has been analyzed,and the performance of all-optical wavelength conversion system based on orthogonal frequency division multiplexing and discrete multi-tone signal is compared in simulation.From the aspects of simple structure,spectral efficiency and system performance,the discrete multi-tone signal is more suitable for a cost-effective all-optical wavelength conversion system.(3)The multi-channel transmission system has been achieved by integrating the twin single-sideband discrete multi-tone modulation technology into the all-optical wavelengthconversion.Firstly,the generation principle of twin single-sideband modulated signal is analyzed in detail,and the all-optical wavelength conversion system of twin single-sideband discrete multi-tone signal with parallel pump and vertical pump structure is simulated and analyzed.In order to improve the spectral efficiency of the system and optimize the factors that affect the conversion efficiency of signal,the converted signals at the remaining frequencies are used to realize the multicast conversion.The multi-channel transmission system based on all-optical wavelength multicasting technology is realized on the basis of the double pump all-optical wavelength conversion system.Through theoretical and simulation analysis,an all-optical wavelength conversion system with low cost,low complexity and high spectral efficiency has been realized.