| 摘要 |
<p>An optical fiber laser comprises a master oscillator serving as a laser oscillator for generating seed light and a power amplifier serving as an optical amplifier for amplifying and outputting laser light emitted from the master oscillator, which is connected at a stage subsequent to the master oscillator. The power amplifier includes plural excitation beam sources, excitation ports which are respectively connected to the plural excitation beam sources and on which excitation beams emitted from the excitation beam sources are incident, a signal port on which the laser light emitted from the master oscillator is incident, an optical coupler having an emission port for emitting the respective excitation beams incident from the excitation ports and the laser light incident from the signal port together, and an optical fiber connected to the emission port. The optical fiber is a photonic bandgap fiber, and has a loss wavelength characteristic in which the photonic bandgap region is narrower than the gain wavelength band in a graph with the horizontal axis representing the wavelength and the vertical axis representing the amount of loss.</p> |
