| abstract |
A tellurite glass as a glass material of optical fiber 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) and a silica-based optical fiber (as a second fiber), optical axes of the first and second optical fibers are held at different angles theta1 and theta2 (theta1<> theta2) respectively from a vertical axis of a boundary surface between their spliced ends, and a relationship between the angles theta1 and theta2 satisfies Snell's law represented by an equation of sin theta1/sin theta2=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. |