| 摘要 |
<p>A laser device has a laser medium responsive to an excitation light for generating a laser beam consisting of a plurality of longitudinal modes when excited by an energy of the excitation light, two mirrors constituting a laser resonator for forming an optical path of the laser beam passing through said laser medium, and a nonlinear optical element, arranged in the laser resonator, for generating a second harmonic caused by one of the plurality of longitudinal modes constituting the laser beam generated in said laser medium and a sum-frequency caused by two of the plurality of longitudinal modes constituting the laser beam generated in said laser medium. Wavelength and phase of the longitudinal modes constituting the laser beam generated in said laser medium are controlled to a condition that said nonlinear optical element generates the second harmonic and the sum-frequency, including a second harmonic and a sum-frequency, or sum-frequency-to-sum-frequency, which have the same wavelength as one another and phases serving to weaken one another.</p> |
