Patent ID: 8625944
Filing Date: 2014-01-07
Classification: G02B

Abstract:
1. An optical-fiber buffer tube, comprising: a polymeric tube defining an annular space; a plurality of optical fibers positioned within the annular space of said polymeric tube, said optical fibers complying with the ITU-T G.652.D recommendations; and a thixotropic composition at least partially filling the annular space of said polymeric tube; wherein said optical-fiber buffer tube possesses a buffer-tube filling coefficient that is substantially 0.30 or higher; wherein, upon subjecting said optical-fiber buffer tube to the mid-span testing according to the USDA Rural Electrification Administration mid-span standard, at a wavelength of 1550 nanometers, (i) each of said optical fibers enclosed within said buffer tube has increased attenuation of no more than 0.1 dB and (ii) said optical fibers enclosed within said buffer tube have a mean increased attenuation of no more than 0.05 dB; wherein, upon subjecting said optical-fiber buffer tube to post-extrusion-shrinkage testing in accordance with the TMA method, said buffer tube exhibits post-extrusion shrinkage (PES) of 0.1 percent or less; and wherein said buffer tube has permanent deformations of less than 10 percent after sheave testing.