| 摘要 |
PURPOSE:To vary laser pulse width without damaging mode lock function by providing a device for varying a beam width inside a laser resonator. CONSTITUTION:An excited light is cast to a laser oscillation element 5 of a laser resonator 2 through a half mirror 1 and a first laser mirror 3, and laser light of a specified wavelength oscillates between the mirror 3 and a second laser mirror 9. A standing wave which is produced in an acoustic optical element 6 modulates laser light; and phase and oscillation of longitudinal mode of laser oscillation spectrum become constant to produce mode lock. Furthermore, a beam width can be changed by a beam width changing means 13 which consists of prisms 11, 12; at least one thereof can rotate freely and changes a laser light incident angle. A pulse width of output laser light can be made variable without damaging mode lock in this way. |
