Development Of QSFP28-4WDM-LR Optical Module For 5G Access Network

Demand of 5G forward network for the performance of optical modules is also increasing with the gradual application and improvement of 5G wireless communication technology,.At present,the huge demand for communication bandwidth,the dense deployment density and the high temperature brought by outdoor communication equipment in 5G access network have put forward higher requirements for the performance of optical modules.In the application of 5G access network,the forward network composed of single wave 25 G optical module cannot fully meet the demands of network design and application.In order to meet the demands of the design and construction of 5G forward network and upgrading of the existing access network,the application of QSFP28-4WDM-LR optical module is imperative.The thesis consists of the following 5 parts: Firstly,the thesis overviews the demand of 5G network and the development of optical module are introduced.Secondly,the characteristics and advantages of CWDM application mode are analyzed,and the 4*25G BASE protocol specification in IEEE802.3bm is introduced.Then,a design scheme of QSFP28-4WDM-LR optical transceiver module is given,and its working principle is analyzed.Next,the performance evaluation standard of 4WDM optical module is introduced,and the preliminary test of the module sample is carried out through design and experiment.Finally,the performance of the module is optimized and retested,and compared with the protocol specification requirements.At the same time,the optimized module is tested at high and low temperatures and 10 km over-fiber transmission.The result indicates that the transmission performance of industrial QSFP28-4WDM-LR optical module is influenced by many factors,including the setting of laser bias current,the design of high-speed circuit near laser and laser driver chip.After optimizing and debugging the module design,the average optical power of the single channel optical transmitter is 0-2 d Bm,the total average optical power of the optical transmitter is less than 8 d Bm,the extinction ratio is 4.5-5.5 d B,the wavelength variation is less than 6.5 nm,the sensitivity of the OMA at the receiving end is better than-12.5 d Bm,and it can work continuously under high and low temperatures.The transmission performance of optical network with multiple passive devices in 10 km is good.Thus,meeting the IEEE802.3bm standards,the QSFP28-4WDM-LR modules can satisfy demands of 5G access network.