Consider the following statements related to optical fiber : 1. Multimode step-index fibers are ideally suited for high-bandwidth, very long-haul applications. 2. Single-mode fibers are generally used on lower bandwidth, shorter haul applications using single-mode injection lasers. Which of the above statements is/are correct?
Statement Analysis: Optical Fiber Types
This solution analyzes the given statements about optical fiber characteristics to determine their correctness.
Multimode Fiber Suitability (Statement 1)
Statement 1 claims multimode step-index fibers are ideal for high-bandwidth, very long-haul applications. This is incorrect because:
- Multimode fibers have larger core diameters, allowing multiple light paths (modes).
- This causes modal dispersion, where different modes travel different distances, leading to signal spreading.
- Modal dispersion limits both the bandwidth and the effective transmission distance.
- Therefore, multimode fibers are better suited for shorter distances and lower bandwidth applications compared to single-mode fibers.
Single-mode Fiber Application (Statement 2)
Statement 2 suggests single-mode fibers are used for lower bandwidth, shorter haul applications. This is incorrect because:
- Single-mode fibers have very small core diameters, allowing only one mode of light propagation.
- This minimal dispersion enables very high bandwidth and significantly longer transmission distances.
- They are the preferred choice for long-haul telecommunications and high-speed data networks.
- Using them for "lower bandwidth, shorter haul" applications would be inefficient utilization of their capabilities.
Conclusion on Statements
Based on the analysis:
- Statement 1 is incorrect.
- Statement 2 is incorrect.
Therefore, neither statement is correct.
Final Answer Determination
Since both Statement 1 and Statement 2 are incorrect, the correct option is the one that indicates neither statement is correct.
Correct Option: D (Neither 1 nor 2)
Important Questions from Optical Fiber
Fibre optic power meters have input for attaching fiber optic connector and detector:
The material used for making optic-fibre cable in general is-
Multimode step-index fiber with a core diameter of 80 μm and a relative index difference of 1.5% is operating at a wavelength of 0.85 μm. If the core refractive index is 1.48, then the normalized frequency for the fiber is
In a multimode fiber (step index), number of modes passing at an operating wavelength of 1300 nm are 1000, the refractive index of the core is 1.50 and that of the cladding is 1.48. The value of core diameter is:
In optical fibers, the Rayleigh scattering is proportional to:
