Rare earth addition optical huaibare - the

摘要

PURPOSE:To obtain a rare earth element addition single-mode optical fiber laser so that it does not have instability, which the conventional one has, in a polarized wave of laser oscillation light, by making an oscillation medium composed of the single-mode optical fiber which retains a double refractive index of a specific value or above and making rare earth elements contained at least in a core of this optical fiber. CONSTITUTION:An oscillation medium in optical fiber laser is composed of a rare earth element addition single-mode optical fiber 10 which retains a refractive index of 5X10-5 or above, and rare earth elements are contained at least in a core 5 of this optical fiber 10. For example, the core part 5 is made of SiO2-GeO2 which contains 100 ppm of Nd, and a clad part 3 is made of SiO2. A difference between a specific refractive index of the core and that of the clad is 0.3%. Further, a stress application part 4 is made of SiO2-B2O3, and a mode double refractive index induced in the core part is about 4.0X10-4. A panda type Nd addition single-mode optical fiber 10 is used. Emission light of semiconductor laser for excitation purpose 6 is made incident to the optical fiber 10 through a polarizer 8.