Recently, Hengtong Optic-Electric (600487), in partnership with China Mobile (600941) and China Mobile Shandong, completed and commissioned the world’s first ultra-low-loss multi-core optical cable line supporting concurrent S+C+L triple-band (Short-wavelength band + Conventional C-band + Long-wavelength band) transmission in Qingdao, Shandong Province. Breaking the inherent capacity ceiling of conventional optical fibre, the milestone rollout marks China’s entry into a new commercialisation era combining space division multiplexing (SDM) fibre and multi-band technologies. It delivers an innovative connectivity blueprint for compute interconnection and ultra-large bandwidth transmission amid the intelligent era, powering China’s optical communications sector to shift from follower to global frontrunner status.
Constrained by limited core counts and insufficient available spectrum resources, legacy optical fibres suffer from prominent bottlenecks in bandwidth and transmission capacity. This pioneering project deploys four-core fibre architecture, accommodating four independent signal pathways within a strand thinner than human hair. Engineers extended ultra-low loss and large effective area performance from the conventional C and L bands into the S band to enable simultaneous triple-band data carriage. The technical upgrade effectively expands digital data highways from dual-lane to three-lane carriage, lifting per-fibre bandwidth by nearly 50% and boosting overall fibre capacity to over five times that of standard single-core alternatives. The upgraded infrastructure is well-positioned to cater to emerging demands including AI intelligent computing and terabyte-level ultra-high-speed data transmission, serving as critical foundational hardware for nationwide compute network construction.
Commercialising multi-core optical cables poses formidable technical hurdles, most notably stringent precision requirements for core alignment and fibre splicing. Against challenges including ambient vibration, complex geographical terrain and sub-micrometre-level splicing tolerance, China Mobile alongside its collaborator Hengtong Optic-Electric broke conventional process boundaries by developing proprietary multi-core splicing algorithms to enable high-precision core alignment and splicing within minutes. The engineering team accomplished high-quality field deployment on live carrier networks, resolving the final set of technical obstacles blocking real-world commercial adoption.
In-service field verification has yielded outstanding performance across all key specifications: across 44 multi-core splice points along the full transmission link, average per-core splicing loss stands at merely 0.089 dB, while the cable’s per-kilometre attenuation drops to 0.189 dB to enable extended transmission reach and superior signal stability. Inter-core crosstalk is controlled below -40 dB per 100 kilometres, enabling near interference-free data delivery. Core metrics covering chromatic dispersion, macro-bending loss and polarisation mode dispersion all satisfy commercial deployment benchmarks, clearing the path for large-scale rollout on existing telecom networks. Real-time full-spectrum S+C+L transmission testing confirmed error-free, low-jitter stable operation across all three bands, solidifying the technology’s robust practical performance under real-world operating conditions.
The world-first commercial launch of this triple-band multi-core optical cable represents a landmark indigenous innovation achievement within China’s optical communications industry. According to China Mobile, the breakthrough technology will underpin interconnections among intelligent computing hubs, large-capacity submarine cable development and the build-out of China’s integrated national computing network. Moving forward, the carrier will keep scaling up next-generation fibre deployment to construct an intelligent optical transport ecosystem featuring higher throughput, lower latency and amplified bandwidth capacity, reinforcing core infrastructure for Digital China development.
As a core development participant, Hengtong Optic-Electric (600487) has further consolidated its leading edge in core optical communications technologies through the landmark project. Going forward, the firm will deepen cross-industry collaborative R&D, targeting breakthroughs in core fields such as low-loss optical materials, low-crosstalk structural design and high-efficiency splicing craftsmanship. Accelerated industrialisation of cutting-edge fibre technologies will equip the AI industry, evolving computing networks and high-quality digital economy growth with robust underlying optical communication infrastructure.