Optical cables are primarily classified by mode, construction, and application environment, with each type optimized for specific distances, bandwidths, and installation conditions.

1. Classification by Mode

Single-Mode Fiber (SMF): Features a small core (8–9 µm) that carries a single light signal, ideal for long-distance, high-speed transmission up to tens of kilometers without signal regeneration. Common types include OS1 (indoor) and OS2 (outdoor, long-haul) fibers . Multimode Fiber (MMF): Has a larger core (50–62.5 µm) allowing multiple light modes simultaneously, suitable for shorter distances such as within buildings or campuses. Multimode types include OM1, OM2, OM3, OM4, and OM5, with OM5 supporting short wavelength division multiplexing for higher bandwidth .

2. Classification by Construction

Tight-Buffered Cables: Each fiber is coated with a 900 µm buffer, commonly used indoors for LANs, patch cables, and short runs . Loose-Tube Cables: Fibers are housed in gel-filled or dry water-blocked tubes, providing protection against moisture and temperature extremes, ideal for outdoor backbones, underground ducts, or aerial installations . Ribbon Fiber Cables: Fibers arranged in flat ribbons (often 12 fibers per ribbon) for high-density splicing, commonly used in data centers . Armored Fiber Cables: Include a protective metal layer to prevent physical damage from rodents, crushing, or accidental digging, suitable for industrial or high-risk outdoor environments . Distribution and Breakout Cables: Distribution cables bundle multiple tight-buffered fibers under a single jacket for space efficiency, while breakout cables individually jacket each fiber for easier termination .

3. Classification by Application Environment

Indoor Cables: Designed for office buildings, data centers, and universities, often with LSZH (Low Smoke Zero Halogen) jackets for fire safety . Outdoor Cables: Built to withstand environmental stress, including UV exposure, moisture, and temperature extremes. Examples include ADSS (All-Dielectric Self-Supporting) for power lines and OPGW (Optical Ground Wire) for high-voltage towers . Specialty Cables:

• FTTH Bow-Type Drop Cable: Flat profile for last-mile installations in apartments or homes.
• Tactical Fiber Cable: Flexible and rugged for rapid deployment in military or broadcast applications.
• Micro Cable (Air-Blown Fiber): Ultra-slim for installation in micro-ducts, allowing scalable fiber capacity .

4. Additional Considerations

Fiber optic cables are also distinguished by jacket type (plenum-rated, riser-rated, general-purpose, LSZH) and connector types (SC, LC, ST, MTP/MPO), which influence installation, safety, and network performance . In summary, the main classifications of optical cables are based on mode (single-mode vs. multimode), construction (tight-buffered, loose-tube, ribbon, armored), and application environment (indoor, outdoor, specialty), with each type tailored to specific network requirements, distances, and environmental conditions.