The rapid spread of generative AI has accelerated the development of CPO for datacenter applications. In CPO, an optical transceiver is placed close to a large-scale LSI (Large Scale Integration) such as a switch ASIC (Application Specific Integrated Circuit) or a GPU (Graphics Processing Unit), and the length of the electrical transmission line can be shortened. Therefore, high-speed communication and low power consumption are expected by CPO. For the deployment of CPO, it is necessary to realize a compact, easy-to-use, detachable optical fiber connector at the edge of the optical transceiver device (Fig. 1).
The newly developed 12-fiber optical connector is significantly smaller than conventional multi-fiber optical connectors, with a connection area that is 1/6 MPO connectors (Fig. 2). The semi-automatic connection method using magnets provides excellent connection workability. The connector can withstand 260°C reflow (the process of soldering components to the substrate) that is necessary to be assembled to a CPO substrate. It also employs optical coupling with lenses, there is very little degradation in characteristics when dust adheres to the optical end face, it is also suitable for dusty environments such as data centers. The connection loss is less than 0.5 dB with good repeatability within ± 0.05 dB.
This developed connector can also be used as a compact multi-fiber optical connector for connecting optical fibers. In addition to high-density attaching to a glass waveguide substrate that is expected to be applied to the next-generation photonics-electronics convergence form (Fig. 3), it is also applicable to more-fiber structures such as 16-fiber. We are currently developing 40-fiber optical connector.
At OFC 2025, which will be held in San Francisco, USA, from March 30 to April 3 this year, we will give an oral presentation (Lecture No. M4J. 2) and exhibit samples (in the booth of Lightera booth No. 2843).
This development is partly based on results obtained from the project, “Research and Development Project of the Enhanced Infrastructures for Post-5G Information and Communication Systems” (JPNP20017), commissioned by the New Energy and Industrial Technology Development Organization (NEDO).
