# Connecting Different Types of Fiber Optic Cables with an Adapter > This patent describes a special adapter that smoothly connects a traditional solid core optical fiber to a newer hollow core optical fiber by carefully changing the light's beam size as it passes between them. - **Patent:** US 12517303 - **Original title:** Optical waveguide adapter assembly - **Owner:** Microsoft Technology Licensing - **Granted:** 2026 - **Status:** Active - **Times cited:** 0 - **Field:** telecommunications, data_centers, optical_networking, semiconductors, consumer_electronics ## What it does The patent details an optical waveguide adapter assembly designed to link two different types of fiber optic cables: a solid core optical waveguide and a hollow core optical waveguide. The core idea is an "optical mode field adapter" that sits between them. This adapter has a waveguiding core whose shape or refractive index property changes the "optical mode field size" of the light signal. Specifically, it transitions the light's beam size from the "first optical mode field size" of the solid core waveguide to the "second optical mode field size" of the hollow core waveguide (Claim 1). This ensures the light signal travels efficiently without significant loss when moving from one fiber type to the other. For instance, if a data center uses traditional silica fibers for short runs but wants to use faster hollow core fibers for longer distances, this adapter would allow a seamless connection. ## What it does NOT cover - Does not cover connecting two solid core optical waveguides without a mode field adapter. - Does not cover connecting two hollow core optical waveguides without a mode field adapter. - Does not cover an adapter that connects different fiber types without actively changing the optical mode field size. - Does not cover systems that exclusively use either solid core or hollow core optical waveguides, but not both. - Does not cover optical connections where the mode field adapter is not directly joined to both the solid and hollow core waveguides as specified in Claim 1. ## The clever bit The innovation lies in the optical mode field adapter's ability to precisely change the optical mode field size of the light signal. This smooth transition, either through shaping the core or adjusting its refractive index, minimizes signal loss when connecting two fundamentally different types of optical waveguides, which typically have incompatible light-guiding characteristics. ## Real-world examples 1. High-speed data center interconnects 2. Telecommunications backbone networks 3. Fiber-to-the-home (FTTH) networks upgrading to advanced fiber types 4. Specialized industrial sensing applications using mixed fiber types 5. Research and development labs testing new fiber optic technologies ## Why it matters Connecting different types of optical fibers, especially newer hollow core fibers, to existing infrastructure is a technical challenge. Hollow core fibers can transmit data faster and with less latency, but their light-guiding properties are different from standard solid core fibers. This adapter allows for efficient integration, potentially enabling upgrades to existing fiber networks without a complete overhaul. It's crucial for industries looking to leverage the benefits of hollow core technology while maintaining compatibility with current systems. ## Frequently asked questions ### What does Connecting Different Types of Fiber Optic Cables with an Adapter cover? This patent describes a special adapter that smoothly connects a traditional solid core optical fiber to a newer hollow core optical fiber by carefully changing the light's beam size as it passes between them. ### Who owns patent US 12517303? Microsoft Technology Licensing owns this patent, granted in 2026. ### When does this patent expire? This patent is expected to expire on March 5, 2044, when the invention enters the public domain. ### What problem does this patent solve? Connecting different types of optical fibers, especially newer hollow core fibers, to existing infrastructure is a technical challenge. Hollow core fibers can transmit data faster and with less latency, but their light-guiding properties are different from standard solid core fibers. This adapter allows for efficient integration, potentially enabling upgrades to existing fiber networks without a complete overhaul. It's crucial for industries looking to leverage the benefits of hollow core technology while maintaining compatibility with current systems. ### What does this patent NOT cover? Does not cover connecting two solid core optical waveguides without a mode field adapter. **Full plain-English explainer:** https://patentbrief.org/patent/us/12517303/optical-waveguide-adapter-assembly **Original patent:** https://patents.google.com/patent/US12517303 --- _Source: PatentBrief — https://patentbrief.org. Patent facts are from public records; the plain-English explanation is PatentBrief's._ ## Related patents Semantically similar inventions in the PatentBrief corpus: - [Routing Light Between Fiber Cores Using Special Reflectors](https://patentbrief.org/patent/us/11646794/fiber-optic-connectors-and-connectorized-fiber-optic-cables-that-include-integra) — This patent describes a fiber optic connector that uses tiny, specially designed reflectors called holographic Bragg gratings to precisely guide light signals from one optical fiber to multiple other fibers, even separating different colors (wavelengths) of light. - [Flexible Silicon Chips That Send Data Using Light](https://patentbrief.org/patent/us/20130230274/photonic-flexible-interconnect) — This patent describes a flexible silicon chip that uses light to send data between different parts of a computer, making connections faster and potentially more compact. - [A Sealed, Stamped Metal Assembly for Guiding Light in Fiber Optics](https://patentbrief.org/patent/us/10761280/hermetic-optical-subassembly) — This patent describes a tiny, sealed optical assembly that uses precisely shaped metal parts and mirrors to guide light signals between a fiber optic cable and an electronic light-emitting or light-sensing device without needing lenses between the main mirrors. - [How to Precisely Connect Light Chips to Optical Fibers](https://patentbrief.org/patent/us/11150423/optical-and-thermal-interface-for-photonic-integrated-circuits) — This patent describes a clever way to accurately align tiny light-emitting components inside a photonic chip with an external optical connector, using a built-in alignment mark and a viewing hole. - [A Photonic Chip Package with Edge Fiber Connections](https://patentbrief.org/patent/us/10598860/photonic-die-fan-out-package-with-edge-fiber-coupling-interface-and-related-meth) — This patent describes a compact package for a photonic chip that integrates electrical components and short optical fibers, allowing direct connection to external optical cables from the side.