Design of bunched optical-fiber parameters for 1.3-µm wavelength subscriber line use

Parameters of bunched GI-optical fiber for use in the 1.3- μm wavelength subscriber line are designed. Suitable fiber parameters were determined mainly from studies concerning transmission loss and crosstalk characteristics. A core diameter around 45 μm and a relative refractive-index difference range from 1.2 to 1.5 percent were found to be suitable for the allowable cladding diameter range from 70 to 90 μ determined by crosstalk and economical considerations. It is also found that a transmission line composed of bunched optical fibers with suitably designed parameter range exhibits a loss level comparable to that composed of the conventional monocore fiber.