| 摘要 |
PURPOSE:To obtain high-efficiency optical amplification function and to easily form the optical waveguide of a smaller size having multipler functions by adding an a growth-assisting dopant to a rare earth element-added layer formed in the central part in the core of a glass waveguide. CONSTITUTION:A rectangular core 3 (refractive index nw; nw>nc1) is formed on a clad 2a which has a low refractive index nc1 and is formed on a substrate 1. The surface of the core 3 and the surface of the clad 2a are coated with a clad 2b (refractive index nc2; nc2<nw). At least one kind of rare earth elements, such as Er, Nd, Yb, Sm, Ce, Ho, and Tm are added to the region of T in the central part of the thickness T direction of the core 3, by which the rare earth element-added layer 4 is formed. The growth-assisting dopant, such as Al, P or Cr, is added together with the above-mentioned elements to this rare earth element-added layer 4. |
