Fiber for optical communication

摘要

A fiber for use in an optical communications system has a core of mainly fused quartz glass of high purity having uniform refractive index in section, and an organic material coated around the outer periphery of said core and having a lower refractive index than that of said core. By choosing the half amplitude width of the incident light beam with respect to the core diameter, the increase in transmission loss due to the excitation of higher order modes is held to a minimum. The loss due to higher order mode excitation is further reduced by choosing a cladding having a dlelectric loss tangent value of about 1000 times the dielectric loss tangent in the core. Thus, the fiber may be used as an optical transmission line.