What is graded-index fiber?
Graded-Index Fiber
Graded-index fiber is a type of optical fiber designed to minimize signal distortion caused by modal dispersion. It achieves this by varying the refractive index of the core in a gradual manner, rather than having a uniform refractive index.
Construction and Principle
The core of a graded-index fiber has a high refractive index at the center which gradually decreases towards the outer edge. This variation in the refractive index creates a lensing effect, causing light rays to follow a curved path and travel at different speeds depending on their distance from the fiber axis.
Advantages
- Reduces modal dispersion
- Increases bandwidth compared to step-index fibers
- Improves signal quality over long distances
Applications
- Long-distance telecommunications
- High-speed data transmission networks
- Local Area Networks (LANs)
Comparison with Step-Index Fiber
| Feature | Graded-Index Fiber | Step-Index Fiber |
|---|---|---|
| Refractive Index Profile | Gradual change | Sharp change |
| Modal Dispersion | Lower | Higher |
| Bandwidth | Higher | Lower |
In summary, graded-index fiber is an advanced type of optical fiber that offers superior performance for high-speed and long-distance communication by effectively managing modal dispersion through its unique refractive index profile.