Analysis of Multimode Insertion Loss Measurements
Application Notes
Introduction
The increased demand for high data rates within the premises network encourages an upgrade of existing systems to 10 Gigabit Ethernet. To achieve gigabit rates laser-based technology can be utilized. While light emitting diodes can be utilized for up to 622 Mbit/s, they cannot physically support faster data rates. Today, 90% of LANs are distributed within 300 meters lengths. The installed fiber base in LAN backbones is 70% graded index multimode fiber of 62.5/125 μm, 20 percent graded index multimode fiber of 50/125 μm, and 10 percent single mode fiber of 8/125 μm. The multimode fiber is qualified at two primary wavelengths: 850 nm (short wavelength) and 1300 nm (long wavelength). The specified bandwidth for 50/125 μm fiber is 500 MHz km at 850 nm and 1300 nm. The bandwidth for TIA/EIA-568-A 62.5/125 μm fiber is 160 MHz km at 850 nm and 500 MHz km at 1300 nm. And the bandwidth for ISO/IEC 11801 62.5/125 μm fiber is 200 MHz km at 850 nm and 500 MHz km at 1300 nm.