Guangtongxin yanjiu (Apr 2025)
Design and Study on 50 Gbit/s Combo PON OLT Optical Module
Abstract
【Objective】As video services gradually become the core pillar of broadband networks, Passive Optical Network (PON) technology has rapidly developed, expanding from the traditional field of home broadband access to a wider range of application areas such as government and enterprise, intelligent manufacturing in industry, and telemedicine. Consequently, the requirements for network bandwidth, latency, packet loss rate, and jitter in terms of service quality have become increasingly stringent. In this condition, the next-generation optical access network technology with a speed of 50 Gbit/s has emerged. The 50 Gbit/s PON is not only required to provide an access bandwidth more than four times that of the 10 Gbit/s PON, but also needs to enhance the service support capabilities, network security protection, and ensure compatibility and smooth evolution with the existing 10 Gbit/s PON technology. In the implementation process, the development of optical transmitter components is particularly crucial.【Methods】The 50 Gbit/s Combo PON Optical Line Terminal (OLT), presented in this study, leverages hybrid integrated package technology to address key challenges such as multi-channel wavelength combination, signal splitting, and crosstalk minimizing. Through meticulous optical path simulations and crosstalk analyses, the device successfully achieves a balance between performance and efficiency.【Results】By means of a meticulously designed 4-channel QSFP28 package size module, the functionality of 3 transmitters and 3 receivers within a metal hermetic tube has been realized. At the same time, thanks to advanced optimization design, the crosstalk from the transmitter to the receiver has been significantly reduced, with an improvement of 20 to 30 dB. This important breakthrough not only enhances the performance of the optical components, but also lays a solid foundation for the commercial deployment of 50 Gbit/s PON.【Conclusion】The test results indicate that the wavelength performance of the optical components proposed in the article fully complies with the requirements of the International Telecommunication Union-Telecommunication Standardization Sector (ITU-T) G.9804.3 international standard. Both the operating eye diagram and sensitivity have reached the expected indicators. This means that the 50 Gbit/s Combo PON OLT optical components are already capable of being applied in actual network environments. Looking to the future, with the continuous progress of technology and the sustained growth of application demands, 50 Gbit/s PON will play an important role in promoting broadband network upgrades, enhancing service support, and improving user experience. It is expected that more innovative achievements will continue to emerge in this field, jointly promoting the prosperous development of optical network technology.
