| 摘要 |
<p>An optical waveguide for a communication system includes a graded index cor formed from at least three glass-forming compounds with a profile having at least two .alpha.-type index profile terms. The core has a refractive index which is nc at the center of the core and which varies as a function of the radial distance r from the center of the core substantially as: where ai is defined by: i = 1 ....N where N ? 2, .DELTA. = (nc2-no2)/2nc2, no is the refractive index of said compounds at r = a, Nc =nc -?dnc/d? where ? is the wavelength of the light source, and the quantities .DELTA.i are parameters which can be varied provided the condition is satisfied.</p> |
