What structural features enable fiber optic cables to transmit data over long distances with minimal loss, and how do they outperform copper cables?

Fiber optic cables use a layered structure for low-loss, long-distance transmission: a glass/plastic core (5-62.5μm) carries light pulses via total internal reflection (cladding with lower refractive index reduces attenuation to <0.2dB/km at 1550nm), protected by a buffer layer, aramid strength members (e.g., Kevlar), and outer PVC/LSZH jacket for durability.   Compared to copper, they offer: 100Gbps per fiber bandwidth (vs. copper’s megabit limits), EMI immunity, smaller/lighter design, and unrepeatered distances >100km (vs. copper’s degradation). These traits make fiber ideal for telecom backbones, data centers, and undersea cables.