Bandwidth of two-core optical cable

The bandwidth of a two-core optical cable depends on the fiber type, with OM2 multimode fiber supporting up to 500 MHz·km and single-mode fiber capable of much higher data rates over long distances.

Multimode Fiber Bandwidth

For multimode fibers, the bandwidth is determined by the modal bandwidth and the distance of transmission: OM1 (62. 5 µm core): 200 MHz·km, suitable for 1 Gbps up to 275 meters and 10 Gbps up to 33 meters (LED source). OM2 (50 µm core): 500 MHz·km, supports 1 Gbps up to 550 meters and 10 Gbps up to 82 meters.

OM3 (50 µm, laser-optimized): 2000 MHz·km, supports 10 Gbps up to 300 meters, 40/100 Gbps up to 100 meters. OM4 (50 µm, laser-optimized): 4700 MHz·km, supports 10 Gbps up to 550 meters, 40/100 Gbps up to 150 meters. OM5 (50 µm, wideband multimode): 28000 MHz·km, designed for short-wavelength division multiplexing (SWDM), supporting multiple 28 Gbps channels over 850–953 nm.

The two cores in a cable can operate independently, effectively doubling the potential data throughput if each core is used for separate channels.

Single-

Mode Fiber BandwidthSingle-mode fiber (SMF) has a much smaller core (8–9 µm) and supports long-distance, high-speed transmission: Typical bandwidth is limited by the electronics rather than the fiber itself. Can carry 10 Gbps to 100 Gbps over tens of kilometers without significant modal dispersion. Two-core single-mode cables can similarly double the effective data channels if each core is used independently.

Practical Considerations

Distance vs. speed: Higher data rates reduce the maximum distance due to dispersion and attenuation. Transceivers: LED sources are used for OM1/OM2, while VCSEL lasers are used for OM3–OM5 for higher speeds. Network design: Two-core cables are often used in duplex configurations, with one core for transmit and one for receive, or for parallel data streams to increase total bandwidth.

In summary, a two-core multimode cable using OM2 fiber can support up to 500 MHz·km, translating to 1 Gbps over 550 meters or 10 Gbps over 82 meters, while single-mode two-core fiber can support much higher speeds over kilometers. The actual bandwidth depends on fiber type, distance, and transceiver technology.