| 摘要 |
PURPOSE:To permit manufacture of graded type optical waveguide by subjecting a crystal added with an impurity to liquid phase epitaxy while maintaining a constant growth temp. to provide a refractive index distribution thereto. CONSTITUTION:The crystal added with the impurity is subjected to the liquid phase epitaxy while the constant growth temp. is maintained by which the refractive index distribution is provided thereto. The Lu2Fe5O12 added with Bi as the impurity is changed in the ratio of Fe2O3 and Lu2O3; R1=Fe2O3/Lu2O3 in the soln. by using PbO, Bi2O3, B2O3 and Fe2O3 as a solvent. Lu in the soln. is decreased by the crystal growth and R1 increases from 12 to 19 before and after the crystal growth when the films are grown respectively to about 100mum thickness on the front and rear of an Sm3Gd5O12 substrate having R1=12. As a result, the substitution quantity of Bi decreases from 1.0 down to 0.6 as X of BixLu3-xFe5O12. The refractive index distribution in the film thickness direction of the optical waveguide consisting of the substrate 10 and the crystal 20 on one face manufactured in the above-mentioned manner is obtd. The graded type optical waveguide is thereby easily obtd. |
