WAVEGUIDE FOR OPTICAL AMPLIFIER AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To obtain a waveguide for a small-size optical antplifier having high gain and high reliability by using a mixture material of specified fluorine compds. to form a high refractive index core with addition of rare earth elements. SOLUTION: A lower SiO2 -based clad layer (first clad layer) 11 having low refractive index is formed on a substrate 10, and a ridge-like core 12 is formed on the first clad layer 11. The core 12 and the first clad layer 11 are covered with an upper SiO2 -based clad layer (second clad layer) 13. The core 12 consists of a mixture material of a fluorine compd. BaF3 having higher refractive index than SiO2 and a fluorine compd. MgF2 having lower refractive index than SiO2 and Er is added to the mixture material as an active element. The first clad layer 11 and the second clad layer 13 consist of SiO2 glass with addition of a fluorine compd. MgF2 having lower refractive index than SiO2 .