SINGLE-MODE OPTICAL FIBER WITH MODE DIAMETER EXPANSION HOLE

摘要

PROBLEM TO BE SOLVED: To provide a single-mode optical fiber with mode diameter expansion holes having cut-off wavelength characteristics and mode field diameter characteristics equal or superior to those of a conventional single-mode optical fiber, specifically a cut-off wavelength characteristic of 1,260 nm or less and a mode field diameter characteristic of 9 μm or more at a wavelength 1,310 nm, and being suitably applicable to construction of an optical transmission line for long-distance large-capacity optical communication.;SOLUTION: The single-mode optical fiber 1 with mode diameter expansion holes includes a core part 11, a clad part 12 having a uniform refractive index lower than that of the core part, and in the clad part area, a plurality of hole parts 13 arranged in the area surrounded by circles individually having a radius R_IN and a radius R_OUT from the center of the core part to be circumscribed with the two circles. In this case, mode field diameter relative change R_MFD is controlled based on dependence of a normalized inscribing circle radius R_IN/a on a normalized frequency V value.;COPYRIGHT: (C)2011,JPO&INPIT