TIA's Glossary of Telecommunication Terms
0-9 | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z
power-law index profile
For optical fibers, a class of graded-index profiles characterized by 
where n (r ) is the nominal refractive index as a function of distance from the fiber axis, n 1 is the nominal refractive index on axis, n 2 is the refractive index of the homogeneous cladding (n (r ) = n 2 when r 
), is the core radius, and g is a parameter that defines the shape of the profile. Note 1: is often used in place of g . Hence, this is sometimes called an alpha profile. Note 2: For this class of profiles, multimode distortion is smallest when g takes a particular value depending on the material used. For most materials, this optimum value is approximately 2. When g increases without limit, the profile tends to a step-index profile.