What is step index and graded index in optical Fibre?

What is step index and graded index in optical Fibre?

STEP INDEX FIBER : The refractive index of the core is uniform throughout and undergoes on abrupt change at the core cladding boundary GRADED INDEX FIBER: The refractive index of the core is made to vary gradually such that it is maximum at the center of the core.

What do you mean by step index?

: an index cut into the fore edge of a book in the form of steps with the edge of each set of leaves preceding an indexed leaf being cut away — compare tab index, thumb index.

How does step index work?

In optical fibers, a step-index fiber is a fiber where a uniform refractive index exists within the core and a sharply decreased refractive index exists in the core-cladding interface because of the lower refractive index in cladding. This significantly limits the bandwidth of step-index multimode fibers.

What makes a step index fiber step index?

In optical fiber, a step index fiber is a fiber characterized by a uniform refractive index within the core and a sharp decrease in refractive index at the core-cladding interface so that the cladding is of a lower refractive index. In a step index fiber, the light rays propagate in zig-zag manner inside the core.

What’s the difference between multimode and single mode step index fibers?

Used for short distance communication. Attenuation of light rays is more in multimode step index fibers but for single mode step index fibers, it is very less. Less expensive. NA of multimode step index fiber is more whereas in single mode step index fibers, it is very less. Pulse broadening and inter modal dispersion is present.

How are rays propagated in a step index fibre?

3. In step index fibres, light rays propagate in a zigzag manner (on zigzag path) inside the fiber Core. These rays travel as meridional rays. It means that the rays cross the axis of fibre for each reflection while propagating. If playback doesn’t begin shortly, try restarting your device.

What does the cross section of a step index cable mean?

This indicates that in step index, core and cladding have their own constant index of refractions N1 and N2 respectively. The step index cable cross section is depicted in the figure-2. In multimode light follows multiple paths through the fiber core.

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