Generally, the process of researching and developing a new optical fibre, and its subsequent large-scale commercialization are a time-consuming endeavor. According to Zhang Lei, it typically involves three main stages.
The first is to complete theoretical validation and get the academia, the industry, upstream and downstream industrial chains on the same page. The second is to foster industrial production capacity and conduct tests under laboratory and existing network conditions. The third is to finalize product types, achieve industry standardization, and initiate large-scale applications in the existing networks.
Take the G.654.E fibre as an example. In 2010, YOFC initiated R&D on optical fibres with ultra-low attenuation and large effective areas. By 2014, prototype samples were completed and received laboratory transmission tests. In 2016, it launched a land application experiment on the first G.654 optical cable under existing network conditions. In 2017, ITU-T organized the release of standards for the G.654.E fibre. From 2018 to 2019, all three major telecom carriers and State Grid completed the verification under the existing networks' service loads. In 2022, the large-scale application of 1-millionfkm G.654.E in the existing network.
Given the lengthy R&D cycle of new optical fibres, the industry needs to anticipate the evolution of optical networks over the next 20 years, as well as new application scenarios. According to Zhang Lei, in terms of R&D progress, the optical communication industry continues to improve the performance of existing optical fibres by flattening wavelengths and reducing attenuation.However, more importantly, the industry needs to identify the next-generation mainstream optical fibres with continuously increasing capacity for the next 20 years or beyond.
The academic and industrial communities are on board that the next-generation optical fibres need to feature high performance, large capacity, and low costs. Based on these characteristics, space division multiplexing (SDM) and hollow-core fibres represent two major technical routes.
SDM refers to a multiplexing method for the transmission of different signals at different spatial positions, similar to adding more lanes to a road to enhance traffic flow.. The common SDM fibres include multi-core, few-mode, and orbital angular momentum fibres.
