written 7.8 years ago by
teamques10
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• modified 7.8 years ago |
Mumbai University > Electronics Engineering > Sem7 > Optical Fiber Communication
Marks: 5M
Year: May2014, Dec2012
|
written 7.8 years ago by
teamques10
★ 64k
|
• modified 7.8 years ago |
| Sr.No. | ||
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| 1 | The refractive index of the core is uniform and step or abrupt change in refractive index takes place at the interface of core and cladding in step index fibers. | The refractive index of core is non-uniform, the refractive index of core decreases parabolically from the axis of the fiber to its surface. |
| 2 | The light rays,propagate in zig-zag manner inside the core. The rays travel in the fiber as,meridional rays and they cross the fiber axis for every reflection. | The light rays propagate in the form of skew rays or helical rays. They will not cross the fiber axis. |
| 3 | Step index fiber is of two types viz; mono mode fiber and multi mode fiber. | Graded index fiber is of only one type,that is multi mode fiber. |
| 4 | The refractive index of the core of step index fiber is constant throughout the core. | The refractive index of the core of the graded index fiber is maximum at center,core and then it decreases towards core-Cladding interface. |
| 5 | The refractive index profile may be defined as:  |
The refractive index profile may be defined as:  |
| 6 | Number of modes for step index fiber,.$M_s=\frac{v^2}2$ V number can be less that 2.405 or more that 2.405 for step index | Number of modes for graded index fiber is $M_s=\frac{v^2}4$,. |
| 7 | Modal dispersion affects signal quality in step index fiber. | Graded index fiber provides zero dispersion as the velocity of modes is changed by changing R.I such that time taken by all modes is same. |
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