| 摘要 |
PROBLEM TO BE SOLVED: To provide a laser which is excellent in exciting light introducing efficiency and laser oscillation efficiency, has a high exciting light resistance, and can be manufactured easily and an optical signal amplifier using the laser. SOLUTION: In the laser and optical signal amplifier in which at least parts of optical fibers which contain a laser activation material and emits laser light from end sections when the material is excited are fixed in a densely aggregated state with an optical medium, polysilsesquioxane containing a repeating unit expressed by the general formula of RSiCO1.5 (wherein, R represents an alkyl group, hydroxyl group, phenyl group, vinyl group, 2-chloroethyl group, 2- bromoethyl group, hydrogen, heavy hydrogen, fluorine, or oxygen except the one which is composed only of oxygen and can vary at every repeating unit) is used as the optical medium. |
