Optical fiber cables are primarily categorized into single-mode and multimode fibers, with further distinctions based on core size, refractive index, fiber count, and cable jacket type.

1. Based on Transmission Mode

• Single-Mode Fiber (SMF): Features a small core diameter of 8–10 µm, allowing only one light mode to propagate. It is ideal for long-distance, high-speed communication with minimal signal loss and is commonly used in metro networks, long-haul communications, and backbone connections .
• Multimode Fiber (MMF): Has a larger core, typically 50 µm or 62.5 µm, supporting multiple light modes. It is suitable for short-distance, high-speed data transmission in LANs, campus networks, and data centers .

2. Based on Refractive Index Profile

• Step-Index Fiber: The core has a uniform refractive index, causing light to travel in straight paths with reflections at the core-cladding boundary. It is simpler but more prone to modal dispersion .
• Graded-Index Fiber: The core's refractive index gradually decreases from the center to the cladding, reducing modal dispersion and improving signal quality over medium distances .

3. Based on Fiber Count

• Simplex: Contains a single fiber strand, typically used for unidirectional transmission or bidirectional transceivers over one fiber .
• Duplex: Consists of two fiber strands, one for transmitting and one for receiving, enabling full-duplex communication .

4. Based on Cable Jacket Type

• OFNR (Riser-rated): Suitable for vertical shafts between floors; cost-effective but releases toxic gases when burned .
• LSZH (Low Smoke Zero Halogen): Emits minimal smoke and no halogen gases, ideal for offices, hospitals, and enclosed public spaces .
• OFNP (Plenum-rated): Offers the highest fire resistance, required for air-handling spaces like ceilings and ducts .

5. Specialty Classifications

• Core Material: Glass or plastic fibers depending on application requirements .
• Connector Types: Various connectors are used to match performance and environmental needs, such as SC, LC, ST, and MPO connectors .
• Wavelength Division Multiplexing (WDM) Compatibility: Some fibers are optimized for carrying multiple channels of data simultaneously using different wavelengths . These categories help determine the appropriate fiber optic cable for specific communication needs, balancing distance, bandwidth, installation environment, and cost considerations.