Optical fiber is an important component of a device used for making fiber directional couplers and for launching and receiving light from an integrated optical. This model is an example of a single step-index waveguide made of silica glass. enough so that the field of confined modes is zero at the exterior boundaries. The step-index profile is used in most single-mode fibers and some multimode fibers. A step-index fiber is characterized by the core and cladding refractive indices n1 and n2 and the core and cladding radii a and b.


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RF broadband signals, such as what cable companies commonly use, cannot be transmitted over multimode fiber.

Step-Index Fiber

This means that the core to cladding diameter ratio is 50 microns to microns and These alternate paths cause the different groups of light rays, referred to as modes, to arrive separately at the receiving point.

Accessories Step Index Fibers The step index fiber SI gets its name from the step-shaped modes of step index fiber of the refractive index between the core glass and the cladding glass Multi-Mode Fibers Description The step index fiber SI gets its name from the step-shaped profile of the refractive index between the core glass and the cladding glass.

The fibers have a small attenuation across a wide wavelength range e.

Refer single mode fiber vs multimode fiber which mentions difference between both modes of fiber. Step index means sharp step in the index of refraction between core and cladding interface.

Lesson Step Index Fiber Modes Archives - Optiwave

This indicates that in step index, core and cladding have their own constant index of refractions N1 and N2 respectively. In some cases, deviations from a step-index profile are intentionally used in order to achieve certain guiding properties.


For example, a region with depressed refractive index between core and cladding can introduce an additional cut-off wavelengthabove which the propagation losses become very high.

Numerical Problems with Step-index Profiles Although the step-index profile is mathematically very simple, it can be somewhat modes of step index fiber in numerical simulations of beam propagation.

Fiber-Optic Technologies > A Brief History of Fiber-Optic Communications

Much lower numerical errors may be achieved e. The index modes of step index fiber should be smoothed just such that it is sampled with a few numerical grid points.

Byglass-clad fibers had attenuation of about 1 decibel dB per meter, fine for medical imaging, but much too high for communications.

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InElias Snitzer of American Optical published a theoretical description of a fiber with a core so small it could carry light with only one waveguide mode. Snitzer's proposal was acceptable for a medical instrument looking inside the human, but the fiber had a light loss of 1 dB per meter.

Communication devices needed to operate over much longer distances and required a light loss of no more than 10 or 20 dB per kilometer. Bymodes of step index fiber critical and theoretical specification was identified by Dr.


Kao for long-range communication devices, the 10 or 20 dB of light loss per kilometer standard. Kao also illustrated the need for a purer form of glass to help reduce light loss.