graded-index fiber

Graded-index (GI) fiber is a type of optical fiber used in telecommunications to transmit data via light signals. Unlike stepped-index fibers, which have a uniform refractive index within the core, GI fibers have a core where the refractive index gradually decreases from the center to the edge. This design helps to reduce a phenomenon called multimode dispersion.12

Multimode dispersion occurs because light rays traveling through the fiber take different paths and arrive at different times, causing the signal to spread out and distort. In GI fibers, light rays traveling through the center of the core move slower than those traveling through the outer parts, effectively causing all rays to arrive at the receiver at roughly the same time. This results in less signal distortion and allows for higher data transmission rates over longer distances compared to stepped-index multimode fibers.2