
- Jacket – The jacket is the external covering of the fiber optic cable. While it offers protection, its primary purpose is not to provide strength. Essentially, the jacket holds all components together: the aramid strength members and buffered fiber, which encompass the optic fiber.
- Aramid strength members – Aramid yarns are strong, heat-resistant fibers. In the fiber optic cable assembly, the aramid strength members provide tensile strength from the connector and throughout the cable. For example, during the manufacturing process, as you pull the cable onto the connector, the aramid strength members help to assure the cable and the glass optic fiber won’t break. (Note that aramid strength members are often referred to as Kevlar®, which is a trademarked name for a particular brand of aramid yarn.)
- Buffer coating on the fiber – The glass optic fiber is manufactured with a protective (buffer) coating against damage. Depending on the patch cord’s application, the buffer coating can be a variety of different materials that will offer, for example, resistance to high temperatures or fire resistance. The buffer also protects the acrylate-coated fiber as it is extruded into the jacket as well as acting as a “seal,” if you will, of that acrylate-coated fiber before splicing or connectorization.
- Optic fiber – Manufactured from glass or plastic, the optic fiber is an optical waveguide comprised of a light-carrying core and cladding, which traps light in the core. Fiber optic communication systems use either single-mode or multimode types.
READ THE FULL BLOG ARTICLE HERE: Introduction to Fiber Optic Cable Assembly Manufacturing Part 1: Components of the fiber optic patch cord and optic fiber geometry
Additional resources from the FOC team include:
- Category Resource
- View the Glossary, Acronyms, Military Specifications for Connectors
- Q&A Resource: email technical questions to AskFOC@focenter.com
Have questions about this FOC Tip?
Contact FOC with questions at: (800) 473-4237 / 508-992-6464 or email: FiberOpticCenter@focenter.com and we will respond ASAP.
This article is an original publication of Fiber Optic Center, Inc. It is shared publicly for educational and reference purposes to support learning and professional development within the fiber optics industry.
You are welcome to read, cite, or reference this material for non-commercial and educational purposes, as long as full credit is given to Fiber Optic Center, Inc. and the author.
Reuse, reproduction, or adaptation of this content — including rewriting, republishing, or incorporating it into new materials (such as websites, blogs, marketing text, technical guides, or AI-generated content) — is not permitted without prior written consent from Fiber Optic Center, Inc.
This material is protected by copyright law upon publication, even if not formally registered.
Use of this content for AI training, automated data extraction, or derivative content generation is prohibited.
Fiber Optic Center monitors and enforces the integrity of its intellectual property through digital identifiers and content tracking.
For more details, please refer to the Fiber Optic Center Content Use and Copyright policy.


