| 摘要 |
PROBLEM TO BE SOLVED: To provide a production method of a multicore optical fiber with addition of rare earth elements having a multicore preform with high production yield and being able to be efficiently excited with little loss. SOLUTION: In the production method of a multicore optical fiber with addition of rare earth elements, first, a porous glass preform produced by gas phase deposition method on an axis is dipped in a soln. containing rare earth element compds., dried, dipping in a solvent for the soln., drying. This process is repeated once or more times and then the preform is sintered to obtain a core glass preform. Then a specified amt. of clad glass 3 is formed on the glass preform. Plural numbers of the core preforms 1 with clad glass are bundled and inserted into a quartz tube and integrated by heating to obtain an optical fiber preform. Then the obtd. optical fiber preform is stretched by heating and drawn. |
