| 摘要 |
PROBLEM TO BE SOLVED: To prevent self-excited pulse oscillation and a large noise by adding a conventional fiber laser in a single mode, which has a certain length and doesn't include rare-earth elements, to a laser cavity resonator to extend the length of the laser cavity resonator. SOLUTION: Radiation from an exciting laser 11 is transmitted to a cladding excitation fiber 20 dopes with ytterbium through a multiple mode fiber 16. The fiber 20 is provided with a single mode core 21 and is doped with ytterbium. The optical fiber in the single mode which doesn't include rare-earth elements is added to the laser cavity resonator to extend the length of the laser cavity resonator so that the distance between the terminal on the lower end side of the optical fiber doped with rare-earth elements and an output coupler may be extended. A length A of the optical fiber in the single mode which is provided between the optical fiber doped with rare-earth elements and a second reflector and doesn't include rare-earth elements is >0.3 L, preferably, >0.5 L (L is the effective length of the laser cavity resonator). |
