Optical amplifier

摘要

A tellurite glass as a glass material of optical fiber (104) and optical waveguide has a composition of 0 < Bi2O3≤20 (mole %), 0≤Na2O≤35 (mole %), 0≤ZnO≤35 (mole %), and 55≤TeO2≤90 (mole %). The tellurite glass allows an optical amplifier and a laser device that have broadband and low-noise characteristics. In a splicing structure of non silica-based optical fiber (as a first fiber) (301) and a silica-based optical fiber (as a second fiber) (302), optical axes (301a, 302a) of the first and second optical fibers (301, 302) are held at different anglesθ1 andθ2 (θ1 NOTEQUALθ2) respectively from a vertical axis of a boundary surface between their spliced ends, and a relationship between the anglesθ1 andθ2 satisfies Snell's law represented by an equation of sinθ1 / sinθ2 = n2 / n1 (where n1 is a refractive index of the first optical fiber and n2 is a refractive index of the second optical fiber) at the time of splicing the first and second optical fibers (301, 302).