Fiber Optic Cabling 101

Multimode Fiber Basic

OM1

• Technical Profile:
Multimode fiber with 62.5 µm core and 125 µm cladding. LED-based transmission at 850 nm and 1300 nm wavelengths. Rated to 200 MHz·km @ 850 nm. Supports 10 Mb to 1 Gb Ethernet — typical max distance ~275 m at 1 Gb. Fails 10GBASE-SR requirements beyond ~33 m. No longer recognized in current TIA-568 or ISO/IEC 11801 standards.

• Deployment Environments:
Legacy campus networks and pre-2000 backbone runs
Retrofit zones with existing OM1 patch panels
Low-speed links in older commercial buildings
Short-range AV, control, or legacy LAN applications

• Installer Consequences:
Orange jacket (default). LC, SC, or ST connectors
Limited bandwidth and modal dispersion risk
Bend radius must be managed in tight trays
Not compatible with MPO/MTP cassettes without adapter
OM1 jacket compounds may limit flexibility compared to newer fiber types

• Specifier Accountability:
Obsolete for new builds. Do not spec for 10 Gb or beyond
Confirm jacket rating (OFNR/OFNP), polish type, and connector geometry
Label clearly and isolate from OM2–OM5 runs
Require documentation of attenuation and modal bandwidth

• Connector Compatibility:
LC, SC, ST — supported
Not compatible with MPO/MTP systems unless adapter or breakout is used
Older OM1 links may use PC or UPC polish — not APC
Termination may require LED-optimized connector geometry

OM2

• Technical Profile:
Multimode fiber with 50 µm core and 125 µm cladding. LED-based transmission at 850 nm and 1300 nm wavelengths. Rated to 500 MHz·km @ 850 nm. Supports 1 Gb Ethernet up to 550 meters. Not suitable for 10 Gb Ethernet beyond ~82 meters. No longer recommended for new high-speed installations. Numerical aperture: 0.20 ± 0.015.

• Deployment Environments:
Mid-2000s commercial buildings and campus links
Retrofit zones with OM2 patch panels
Low-speed backbone runs with verified OM2 stock
Short-range AV, control, or legacy LAN applications

• Installer Consequences:
Orange jacket (default). LC or SC connectors
Modal dispersion limits 10 Gb performance
Bend radius must be respected in legacy trays
Not compatible with MPO/MTP cassettes without adapter
Jacketed OM2 may lack flexibility compared to laser-optimized fiber

• Specifier Accountability:
Acceptable for 1 Gb Ethernet only
Do not spec for 10 Gb or high-density MPO deployments
Confirm jacket rating (OFNR/OFNP), polish type, and connector geometry
Label clearly and isolate from OM3–OM5 runs
Require documentation of attenuation and modal bandwidth

• Connector Compatibility:
LC, SC — supported
MPO requires adapter or cassette swap
Older OM2 links may use PC or UPC polish — not APC
Termination may require LED-optimized connector geometry

OM3

• Technical Profile:
Laser-optimized multimode fiber with 50 µm core and 125 µm cladding. Rated to 2000 MHz·km @ 850 nm. Supports 10 Gb Ethernet up to 300 meters and short-range 40/100 Gb Ethernet up to 100 meters. Designed for VCSEL-based transmission at 850 nm. Bend-insensitive variants available. Recognized in TIA-568 and ISO/IEC 11801 standards.

• Deployment Environments:
Data centers, telecom rooms, and backbone links
Commercial buildings with 10 Gb switches
MPO-based patching environments
Short-range aggregation zones and high-speed AV deployments

• Installer Consequences:
Aqua jacket (default). LC or MPO connectors
Bend-insensitive variants reduce routing constraints
Must confirm polarity and strand count in MPO deployments
Cassette compatibility and connector mapping must be validated
Requires laser-optimized cleaning and inspection protocols

• Specifier Accountability:
Acceptable for 10 Gb Ethernet and short-range 40/100 Gb
Confirm jacket rating (OFNR/OFNP), bend radius, and cassette compatibility
Document polarity, connector mapping, and strand count
Label clearly and isolate from OM1/OM2 runs
Require attenuation and insertion loss documentation for MPO links

• Connector Compatibility:
LC, MPO — supported
SC and ST not recommended due to polish type and modal mismatch
MPO requires polarity documentation and cassette alignment
Compatible with duplex and parallel optics depending on deployment

OM4

• Technical Profile:
Laser-optimized multimode fiber with 50 µm core and 125 µm cladding. Rated to 4700 MHz·km @ 850 nm. Supports 10 Gb Ethernet up to 550 meters and 40/100 Gb Ethernet up to 150 meters. Designed for VCSEL-based transmission. Bend-insensitive variants are standard. Recognized in TIA-568 and ISO/IEC 11801 standards.

• Deployment Environments:
High-performance data centers and telecom rooms
MPO-based patching and cassette systems
Backbone links requiring extended 10 Gb reach
Short-range aggregation zones and parallel optics deployments

• Installer Consequences:
Aqua or Erika Violet jacket. LC or MPO connectors
Bend-insensitive variants standard — reduces routing constraints
Polarity and cassette mapping critical for MPO deployments
Requires laser-optimized cleaning and inspection protocols
Strand count must match transceiver and cassette configuration

• Specifier Accountability:
Preferred for 10/40/100 Gb multimode deployments
Confirm jacket rating (OFNR/OFNP), bend radius, and MPO cassette spec
Require documentation of polarity, strand count, and insertion loss
Label clearly and isolate from OM1–OM3 runs
Verify compatibility with parallel optics and breakout configurations

• Connector Compatibility:
LC, MPO — supported
SC and ST not recommended due to polish type and modal mismatch
MPO requires polarity documentation and cassette alignment
Compatible with duplex and parallel optics depending on deployment

OM5

• Technical Profile:
Wideband multimode fiber with 50 µm core and 125 µm cladding. Rated to 28000 MHz·km @ 850 nm. Supports shortwave wavelength multiplexing (SWDM) across 850–950 nm range. Optimized for 40/100 Gb Ethernet over multiple wavelengths — up to 150 meters. Designed for VCSEL-based transmission. Bend-insensitive variants are standard. Recognized in TIA-568 and ISO/IEC 11801 standards.

• Deployment Environments:
Advanced data centers with SWDM transceivers
MPO-based high-density patching systems
Backbone links requiring wavelength multiplexing
Parallel optics zones and short-range aggregation layers

• Installer Consequences:
Lime green jacket (default). LC or MPO connectors
Bend-insensitive — reduces routing constraints
Polarity and strand mapping critical for MPO deployments
Must confirm SWDM transceiver compatibility
Requires laser-optimized cleaning and inspection protocols

• Specifier Accountability:
Acceptable only where SWDM is deployed
Confirm jacket rating (OFNR/OFNP), cassette spec, and transceiver match
Require documentation of wavelength plan, strand count, and insertion loss
Label clearly and isolate from OM1–OM4 runs
Verify compatibility with parallel optics and breakout configurations

• Connector Compatibility:
LC, MPO — supported
SC and ST not supported due to polish type and modal mismatch
MPO requires polarity documentation and cassette alignment
Compatible with duplex and parallel optics depending on deployment

Singlemode Fiber Basic

OS1

• Technical Profile:
Singlemode fiber with 9 µm core and 125 µm cladding. Indoor-rated per IEC 60793-2-50 Type B1.1. Supports 1–100 Gb Ethernet over long distances — up to 10 km at 1310 nm and 40 km at 1550 nm depending on transceiver and link budget. Laser-based transmission using Fabry–Pérot or DFB lasers. Attenuation typically ≤ 1.0 dB/km @ 1310 nm. Not bend-insensitive unless specified.

• Deployment Environments:
Indoor backbone runs in commercial buildings
Telecom rooms and riser closets
Long-range links within campus environments
Enterprise LANs and high-speed switch uplinks

• Installer Consequences:
Yellow jacket (default). LC or SC connectors
Laser-based transmission — eye safety precautions required
Bend radius critical — especially in riser trays and patch enclosures
Jacket must match fire code (OFNR for riser, OFNP for plenum)
Requires precise cleaning and inspection of connector endfaces

• Specifier Accountability:
Acceptable for all singlemode indoor deployments
Confirm jacket rating, connector type, polish geometry, and insertion loss
Document polarity and strand count for duplex or MPO configurations
Label clearly and isolate from OS2 outdoor-rated runs
Verify compatibility with transceiver wavelength and power budget

• Connector Compatibility:
LC, SC — supported
MPO supported with proper cassette and polarity mapping
APC polish may be required for certain applications (e.g., RF overlay)
Not compatible with multimode connectors or polish types

OS2

• Technical Profile:
Singlemode fiber with 9 µm core and 125 µm cladding. Outdoor-rated per IEC 60793-2-50 Type B1.3. Supports 1–100 Gb Ethernet over long distances — up to 10 km at 1310 nm and 40+ km at 1550 nm depending on transceiver and link budget. Laser-based transmission using DFB or EML lasers. Attenuation typically ≤ 0.4 dB/km @ 1310 nm. Bend-insensitive variants available.

• Deployment Environments:
Outdoor backbone runs and campus links
Direct burial, conduit, or aerial installations
Long-haul telecom and ISP infrastructure
Municipal networks and inter-building fiber routes

• Installer Consequences:
Yellow jacket (default). LC or SC connectors
UV-resistant and water-blocking variants available
Rodent-resistant armor may be required in exposed zones
Bend radius and pulling tension must be managed during installation
Requires precise cleaning and inspection of connector endfaces

• Specifier Accountability:
Required for outdoor singlemode deployments
Confirm jacket rating (UV, water-blocking, rodent-resistant)
Document polarity, strand count, and termination method
Label clearly and isolate from OS1 indoor runs
Verify compatibility with transceiver wavelength and power budget

• Connector Compatibility:
LC, SC — supported
MPO supported with proper cassette and polarity mapping
APC polish may be required for certain applications (e.g., RF overlay)
Not compatible with multimode connectors or polish types

Hybrid Fiber Cable (Power over Fiber)

Composite Cable

• Technical Profile:
Composite cable integrating optical fibers for data and copper conductors for power. Supports high-bandwidth transmission alongside low-voltage DC delivery.
Fiber strands may be singlemode or multimode; copper conductors typically 16–12 AWG depending on load.
Jacket may be riser-rated (OFCR), plenum-rated (OFCP), or outdoor-rated (OSP) with water-blocking, UV resistance, and optional rodent protection.
Used in environments where separate power runs are impractical or where remote devices require both connectivity and power.

• Deployment Environments:
Security cameras, wireless access points, and sensors in remote or outdoor zones
Smart poles, kiosks, and perimeter enclosures
Industrial automation zones with long-distance device drops
Transit systems, tunnels, and infrastructure with limited conduit space
Temporary installations where conduit access is restricted

• Installer Consequences:
Larger OD and mixed termination requirements (fiber + copper)
Requires coordination between fiber termination and low-voltage power crew
Bend radius and pulling tension must be managed across both media
Jacket memory and compound vary by manufacturer and environment
May require staggered termination zones and dual test protocols

• Specifier Accountability:
Confirm fiber type (OM/OS), copper gauge, and jacket rating
Require documentation of power capacity, flame rating, and termination method
Do not substitute standard fiber or copper in hybrid-required zones
Label clearly and isolate from single-media bundles
Verify compliance with NEC Article 770 and low-voltage power standards

• Connector Compatibility:
Fiber: LC, SC, MPO depending on strand count
Power: typically unterminated or pre-terminated with DC barrel, Molex, or custom connectors
Connector strain relief and separation protocols may be required

Fiber Jacket Types

OFNR (Optical Fiber Nonconductive Riser)

Description:
Rated for vertical runs between floors in non-plenum spaces. Flame-retardant per NEC Article 770, but not smoke-rated.

Use Case:
Acceptable for riser closets, telecom rooms, and conduit-protected backbone runs.

OFNP (Optical Fiber Nonconductive Plenum)

Description:
Rated for air-handling spaces such as drop ceilings and plenum zones. Provides the highest flame and smoke resistance available for fiber cabling.

Use Case:
Required by code in any exposed plenum environment, including return-air plenums and HVAC-integrated ceiling spaces.

LSZH (Low Smoke Zero Halogen)

Description:
Designed for international deployments and confined spaces. Emits minimal smoke and no halogen gases when burned, reducing toxicity and corrosion risk.

Use Case:
Used in transit systems, tunnels, and global projects with environmental toxicity constraints or international fire codes.

OSP (Outside Plant)

Description:
Jacketed for direct burial, aerial, or conduit installations. UV-resistant, water-blocking, and rodent-resistant variants available depending on environment.

Use Case:
Required for outdoor backbone runs, campus links, and inter-building fiber routes exposed to environmental hazards.

Armored

Description:
Includes interlocking steel or corrugated aluminum armor beneath the outer jacket. Provides enhanced crush resistance and rodent protection.

Use Case:
Used in high-risk environments such as industrial zones, transit tunnels, and exposed conduit runs. May be riser-rated (OFCR) or plenum-rated (OFCP) depending on outer jacket compound and flame rating.