GAIN PHOTONIC CRYSTAL OPTICAL FIBER, LASER AMPLIFICATION SYSTEM, AND SETTING METHOD FOR GAIN PHOTONIC CRYSTAL OPTICAL FIBER

摘要

PROBLEM TO BE SOLVED: To restrain amplified spontaneous emission or parasitic oscillation in a codoped optical fiber. SOLUTION: In a codoped optical fiber, an additive to function as a sensitizer is excited by the energy injected by a laser beam so that energy is applied to an additive to function as an activator based on the excitation level. In the case the refractive index guide type photonic crystal optical fiber (PCF) is used in a bent state, its loss is increased to a shorter wavelength side. Utilizing the propagation characteristics, the PCF is used in a radius of curvature so that the loss is small with a wavelength in a gain spectrum of the activator and the loss is large with a wavelength in a gain spectrum of the sensitizer (