Fiber Optic Basics: What Matters Most for OEMs

A Look at Fiber Types, Assembly Options, and How to Choose the Right Manufacturing Partner

Fiber optic cables power the world’s fastest, most reliable data systems—from medical devices and aerospace equipment to telecom networks and industrial automation. These cables use pulses of light to transmit information through ultra-thin glass or plastic fibers, enabling high-speed, long-distance communication with minimal signal loss.

When it comes to fiber optic cable assemblies, there’s more to consider than just the cables. OEMs need fully integrated solutions—complete with the right connectors and performance specifications—to ensure seamless installation and system performance.

Fiber Optic Cable

If you’re reading this and are involved in the industry, you already know the essentials (and you might want to jump down to the section in this article about what OEMs should look for in a manufacturing partner).

To establish foundational knowledge, let’s cover the basics: what is a fiber optic cable? It’s a specialized cable that transmits data as pulses of light through ultra-thin strands of glass or plastic. Each fiber has a core that carries the light, cladding that keeps the light from escaping and reflecting it back to the core, outer protective jacket for durability and environmental protection. Connectors suitable for the application are essential components that enable the connection and disconnection of fiber optic cables to respective devices, allowing light signals to be efficiently and reliably transmitted between devices with minimal loss. These cables make high-speed, long-distance, and high-capacity data transmission possible with very little signal loss, making fiber optic technology superior to traditional copper cabling in many applications.

Types of Fiber Optic Cable

By Transmission Type:

Single-mode and multi-mode fibers are two main types of optical fiber used for data transmission. 

• Single-Mode Fiber (SMF):
  • Has a smaller core (around 9 microns), allowing only one light mode to propagate, making it suitable for longer distances and high-bandwidth/high-speed applications.
  • Think telecom backbones or big data centers.
    
    
• Multi-Mode Fiber (MMF):
  • Has a larger core (50 or 62.5 microns), supporting multiple light modes.
  • Typically used for shorter distances.
  • Comes in a few types (OM1, OM2, OM3, OM4, OM5) that vary by core diameter, light source, bandwidth and distance.
  • OM1 and OM2 primarily use LED light sources and are typically suitable for older networks and shorter distances.
  • OM3, OM4, and OM5 primarily utilize laser-based light sources to support higher speeds, and are suitable for modern applications such as data centers and local area networks. 
  • Higher OM numbers generally indicate higher bandwidth capabilities, allowing for faster data transmission over longer distances. 
  • Jacket Color: OM1 and OM2 are often orange, while OM3 and OM4 are typically aqua. OM5 is a newer type with a water green jacket. 

By Construction:

Primarily, the differences lie in the level of protection and durability required for each environment. Indoor cables prioritize flexibility and fire safety for enclosed spaces, while outdoor cables are engineered to endure the rigors of external elements and physical stresses. Selecting the right type of fiber optic cable based on the intended environment and application is crucial for optimal performance and longevity of your network infrastructure. 

• Indoor Cables: 

Typically lightweight, flexible and compact—easy to install and compatible with controlled indoor environments. They often use tight-buffered construction where individual fiber strands are tightly surrounded by a protective buffer, and are required to meet fire safety standards and codes relevant to indoor installations.

Commonly jacketed with materials such as PVC (polyvinyl chloride) or LSZH (low- smoke zero halogen); LSZH is preferable where fire safety is a concern, as it emits minimal smoke and toxic fumes when exposed to flames.

Applications include office buildings, data centers, and connectivity between network devices.

• Outdoor Cables: 

Essential for long-distance telecommunications networks, inter-building connectivity, outdoor surveillance systems, broadband infrastructure, and deployments in challenging outdoor environments like rural areas and industrial complexes. 

More robust and ruggedized construction with multiple protective layers to withstand harsh outdoor conditions and a wide range of temperatures (from extreme cold to high heat).

They may employ loose-tube construction, where fibers are placed in gel-filled tubes, providing protection against moisture, and typically feature UV-resistant jackets made of materials like polyethylene (PE) or polyvinylidene fluoride (PVDF) for protection against sun damage, moisture, and temperature fluctuations.

They may include additional layers or armor for protection against physical damage caused by rodents, vibration, or impact. They can be installed using burial, aerial, or duct methods, requiring careful consideration of factors like cable tension and grounding.

• Specialty Cables: 

Specialty fiber optic cables are designed for specific applications requiring unique performance characteristics, often going beyond the capabilities of so-called standard communication fibers. A few examples: armored cables, plenum-rated cables for airspaces, self-supporting lines for specific installations.

Standard communication fibers prioritize signal transmission with low loss over distance and high bandwidth. However, specialty fibers are tailored for diverse applications such as sensors, lasers, filters, amplifiers, and more.

While standard fibers primarily use silica glass and have a consistent core/cladding diameter (typically 125µm), specialty fibers exhibit hundreds of variations in glass composition, core/cladding structures, and tailored optical properties. These fibers can incorporate special dopants (like erbium for amplifiers), birefringence for polarization-maintaining properties, multiple claddings, and tailored refractive index profiles to manipulate light in specific ways for myriad applications. 

• Polarization-Maintaining (PM) fibers: Designed to preserve the polarization state of light, crucial for applications like advanced sensors and laser systems.
• Active fibers: Doped with rare-earth ions (like erbium) to amplify optical signals, essential for long-distance communication networks.
• Photonic Crystal Fibers (PCFs): Feature a unique structure with air holes in the cladding, allowing for diverse light guidance and manipulation possibilities.
• Hollow-core fibers (HCFs): Offer reduced latency and potentially higher bandwidth by guiding light through a hollow core filled with air or a vacuum.
• Multi-core fibers (MCFs): Increase data capacity by incorporating multiple independent cores within a single fiber.
• Fibers optimized for harsh environments: Such as high-temperature polyimide-coated fibers or radiation-resistant fibers for nuclear or space applications. 

By Material:

Glass and plastic fibers differ significantly in their properties and applications. Glass optical fibers generally offer superior performance for long-distance, high-bandwidth applications due to lower signal loss and higher transmission speeds, while plastic optical fibers are well-suited for short-distance, lower-speed applications where cost and flexibility are important factors.

Fiber Optic Assemblies

Fiber optic assemblies are complete, ready-to-go cable systems that include fiber optic cables, connectors, and often additional components such as adapters, splitters, or protective sheathing. They are designed for rapid, reliable installation and integration into larger systems.

Common Types of Assemblies:

• Single-Mode Fiber (SMF): Features a small core and support a single light path. Ideal for long-distance, high-bandwidth applications like telecom and data centers.
• Multi-Mode Fiber (MMF): Features a larger core, allowing multiple light paths. Best for shorter distances, commonly used in local networks and building systems.
• Patch Cords & Jumpers: Short, easy connection cables.
• Pigtails: One end is connected; the other is ready for splicing.
• Trunk Cables: Bundled, multi-fiber assemblies for large-scale setups.
• Custom Bundles: Special designs for imaging, sensing, lighting, etc.
• Pre-Terminated Assemblies: Plug-and-play solutions built and tested before they arrive.

Fiber optic assemblies can come with lots of different connector types (LC, SC, ST, FC, MPO/MTP, SMA) and are often custom-built for length, performance, and environmental needs.

Where Fiber Optic Assemblies Are Used

You’ll find fiber optic technology in critical sectors such as healthcare, defense, aerospace, smart infrastructure, and education—where speed, security, and precision are non-negotiable.

Fiber optic cables and assemblies are behind the scenes in some of the world’s most important systems:

• Telecom & Internet: They’re the backbone of the global voice, data, and video networks, from undersea cables to 5G and FTTH deployments.
• Data Centers: Essential for fast, high-density interconnects for servers and storage.
• Healthcare: Used in imaging, endoscopy, diagnostics, and surgical tools (such as laser surgery), and high-speed hospital data networks.
• Defense & Aerospace: Provide secure, EMI-immune communications; navigation and control systems in aircraft and spacecraft.
• Broadcasting: Handle live video transmission, studio interconnects, and event streaming.
• Industrial Automation & Energy: Used in process control, factory automation systems, smart grid communications, pipeline monitoring, and energy management.
• Education & Research: Support campus networks, remote learning, and high-speed research collaboration.
• Smart Cities: Help run and manage traffic systems, surveillance and security networks, and infrastructure monitoring.

What OEMs Should Look for in a Manufacturing Partner

When you’re outsourcing fiber optic assemblies, choosing the right manufacturing partner can make or break your project. You need more than just technical capability—you need a partner who can meet your quality, timeline, and regulatory demands while helping you navigate supply chain and product development complexities.

OEMs need to prioritize a host of variables when evaluating a manufacturing partner for fiber optic cable and assembly production.

This is what matters:

• Clear Specs & Documentation
  Provide all the details—drawings, fiber counts, connector types, lengths, and special environmental needs. Be specific about performance (like insertion/return loss) and any required compliance (RoHS, REACH, etc.).
• Robust Quality & Process Control
  Look for a CM with comprehensive end-to-end testing—insertion/return loss, Optical Time Domain Reflectometer (OTDR), environmental validation—and documented quality and validation processes.
• Custom Capabilities & Flexibility
  You need a partner who can handle custom builds, quick-turn prototyping, and scale production up or down as your project evolves.
• Strong Communication & Engineering Support
  A good CM offers design-for-manufacturability (DFM) assistance, fast feedback, and clear project updates—not just assembly work.
• Supply Chain Strength & Stability
  Can they source specialty parts? Can they navigate material shortages? A qualified CM is proficient in contingency planning, has multi-site production, and strategies to manage tariff, duty, and logistics issues. Learn more about Agility Tech’s strategies here.
• Regulatory Readiness & Compliance Expertise
  Make sure they know how to work in regulated sectors (such as medical or aerospace) and hold the requisite certifications like ISO 13485 and ITAR.
• Efficiency & Cost Control
  Outsourcing should cut your costs and simplify your supply chain. Look for turnkey solutions that reduce overhead and speed up delivery, while ensuring compatibility with current and future needs.

Bottom Line

Fiber optic technology is a must-have in today’s technologically advanced world with an insatiable need for higher-speed/higher-bandwidth, reliable data transmission across a wide range of industries and applications. When OEMs partner with experienced, communicative, and quality-focused manufacturers, they can move faster, mitigate risk, and deliver precision products with confidence—even out-pacing today’s fast-moving industries.

Your Fiber Optic Partner, Beyond Assembly

At Agility Tech, we’re more than a supplier—we’re a committed partner that strives to enhance your designs, improve manufacturability and efficiency, streamline your supply chain, and help you bring your innovations to market faster.

Let’s talk about:

• Early design collaboration (DFM)
• Supply chain strategies
• Production scalability and cost reduction initiatives
• Quality and compliance alignment

When precision matters, trust a partner who’s built to deliver.

Ready to Start?

Contact us today to explore how our fiber optic assembly solutions can help you move faster, lower costs, and mitigate risk—without compromising performance.

Let’s Connect! 

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