Design And Implementation Of 400gb/s QSFP-DD Transmitter Optical Subassembly

The fifth-generation mobile communication technology is reaching the commercialization process.New services in the communications industry and the high index requirements of 5G technology pose new challenges to the 5G bearer network architecture and technical solutions at various layers.As the basic component units of communication networks,traditional optical modules can no longer meet the high-bandwidth requirements of Ethernet.Optical modules with higher-bandwidth are proposed for using.IEEE released the Ethernet standard IEEE 802.3cn for 400 G optical modules in January 2019,which has laid the foundation for the commercialization for 400 G QSFP-DD optical modules.Optical module manufacturers actively carry out the research and development of 400 G QSFP-DD optical module around 5G application.The difficulty of 400 G optical module is that with the increase of transmission distance,the link dispersion is serious and the loss increases,which puts forward higher requirements for the design of 400 G optical module with transmission distance more than 2km.Based on this background,this thesis mainly studies the eight channel combining scheme and the impedance matching of RF circuit,then designs and realizes EML transmitter optical subassembly with transmission rate of 400Gb/s,transmission distance of 10 km to 40 km and packaging form meeting QSFP-DD specification.The main work of this thesis is as follows.(1)According to the requirements of relevant standards,the overall design plan of the optical transmitter module includes the design of high frequency circuit and electromagnetic simulation calculation,optical path design and tolerance analysis,and thermal simulation calculation.(2)Electromagnetic simulation software is used to simulate the characteristic impedance and S parameters of the radio-frequency circuit.And matching structure at the interconnection of the optical transmitter component is designed to meet the impedance matching requirements of the radio-frequency circuit,so as to obtain lower reflection and lower insertion loss and thus ensuring the steady operation of the optical transmitter module.(3)And this thesis introduces the packaging technology and test system of 400Gb/s QSFP-DD optical transmitter module which carried out the tests for experimental samples.