| 摘要 |
PROBLEM TO BE SOLVED: To provide an amplifier such that power and output mode quality of light to be amplified are easily adjusted.SOLUTION: The laser amplifier is constituted including a solid gain medium 1 which receives the light 6 to be amplified from one end surface 11 and emits it from the other end surface 12, an excitation light source 5 which irradiates the gain medium 1 with excitation light 7 to amplify the light 6 to be amplified, and a 1/2-wavelength plate 2 which is interposed between the gain medium 1 and the excitation light source 5 and can be rotated so as to pass the excitation light 7. The laser amplifier changes the polarization direction of the excitation light 7 with which the gain medium 1 is irradiated and, therefore, easily increases or decreases a degree of absorption of the excitation light 7 through the rotation of the 1/2-wavelength plate 2. Consequently, while the output mode quality of the light 6 to be amplified is maintained by suppressing thermal strain of the gain medium 1, the power of the light 6 to be amplified is easily increased up to a necessary sufficient level. |
