PURPOSE: To obtain an optical star coupler which is easy to produce and has less insertion loss, by arranging one optical fiber and an optical fiber bundle consisting of plural fibers so that they face to each other and arranging a lens between them so as to satisfy prescribed conditions.
CONSTITUTION: One optical fiber 13 and an optical fiber bundle consisting of plural optical fibers 14W20 are arranged so that they face to each other, and a lens 21 is arranged between them. The ratio of the radius of the core of the incidence fiber 13 to the radius of the smallest circle 23 including diameters of cores of exit fibers 14W20 is approximately equal to the magnification of the lens 21. In this constitution, though the loss due to the light incident to the clad part is generated, the insertion loss is not generated when the light incident to the exit fiber is reflected by the other end and is returned and is made incident to the optical fiber 13 through the lens 21. Consequently, an optical star coupler which is easy to produce and has less insertion loss is obtained.
SERIZAWA AKIMOTO
ISHIZUKA SATOSHI
KUBO KIYOSHI
OOKAWA YASUHITO
