Design And Implementation Of 4x25Gb/s EML Transmitter Optical Subassembly Applied In 5G Wireless Network

In order to meet the demand for capacity improvement of transmission pipelines based on the existing bearer network and the large scale construction of 5G networks in the future,it is practically significant that the 100 G CFP(Centum Form-factor Pluggable)optical module with large size and high power dissipation will be replaced by a 100 G QSFP(Quad Small Form-factor Pluggable)28 optical module with smaller size and lower power dissipation.The hybrid-integrated 4x25Gb/s EML optical transmitter subassembly is a key optoelectronic device used in the 100 G QSFP28 optical module which is important for high-speed long-distance optical communication systems.Because of its small package size,good high speed performance,high reliability and suitable for long-distance transmission,it is indispensable for the future 5G mobile communication system and it is a key research subject of globally renowned optical device manufacturers and research institutions.The thesis was carried out on this background.The design and implementation of an EML transmitter optical subassembly that meets with the customers' requirements is completed.The component can be used in the 100 G QSFP28 optical module.I believe it will soon be applied to the construction of 5G wireless communication system in the near future.This thesis mainly discusses:(1)The Mechanical dimensions of the 4x25Gb/s hybrid integrated EML optical transmitting assembly are designed.(2)Simulation of the port impedance and S parameter of RF flexible circuit board is given by using CST microwave studio.An RF flexible circuit board with impedance matching,low reflection and low insertion loss is obtained.A filter circuit is designed in order to ensure the stability of the laser diode.(3)The entire optical system is designed with the help of ZEMAX optical simulation software.Through the careful analysis of Gaussian beam and the method of physical optical propagation,the various schemes of collimation,focusing and optical multiplexing of the optical system are confirmed.Finally,tolerance analysis of the whole optical system is given by using ZEMAX physical optical propagation method.(4)The packaging technology of 4x25Gb/s hybrid integrated EML transmitter optical subassembly is introduced.And a lot of tests on the experimental prototype is carried out.