| 摘要 |
PURPOSE:To increase a lens interval and to install plural isolators by providing a 2nd lens at the position where the converged light of a 1st lens becomes diffused light and arranging two isolators between the both. CONSTITUTION:The projection light 8 from a semiconductor laser 1 is converged by the 1st lens 2, the 2nd lens 3 is arranged at the position where the converged light is converted into the diffused light, and the light is converged by this lens 3 on the incidence end surface of the optical fiber 4. Then the two optical isolators consisting of magnetooptic crystal 7, a polarizer 5, an analyzer 6, and a magnet 9 are installed between the 1st lens 2 and 2nd lens 3. Consequently, the interval between the two coupling lenses can be made large, so while a decrease in coupling efficiency is suppressed as much as possible, the optical isolators can be installed. |
