Optical Fiber Preform

Abstract

To provide an optical fiber capable of suppressing the volatilization of a dopant raw material such as germanium dioxide by controlling a set position of a core part deposition burner in a large-sized optical fiber preform to form a suitable refractive index distribution and having improved optical properties, such as a zero dispersion wavelength.SOLUTION: An optical fiber preform includes a core part having a relatively high refractive index and a cladding part having a low relatively refractive index. When setting a position having 45% value of a refractive index difference between the center of the core part and the cladding part to a boundary rcore (mm) between the core part and the cladding part and setting a radius position r having the maximum refractive index difference between the center of the core part and the cladding part to rside (mm), rside / rcore is 0.745-1.00.SELECTED DRAWING: Figure 3