METHOD FOR STABILIZING HIGHER HARMONIC OUTPUT AND SHORTWAVELENGTH LASER BEAM SOURCE UTILIZING THE SAME

摘要

PURPOSE: To stabilize the optical characteristics of the emitted higher harmonic wave after conversion at the time of making the basic wave from a short- wavelength laser beam source for which a semiconductor laser is used incident on an optical wavelength conversion element and converting this basic wave to the higher harmonic wave. CONSTITUTION: The semiconductor laser beam P1 is made incident on the optical waveguide 2 of the optical wavelength conversion element 22a formed with a polarization inversion region 3 and optical waveguide 2 on an LiTaO3 substrate 1 and blue light is obtd. by subjecting this laser beam to wavelength conversion. At this time, the driving current of the DBR part 40 of the DBR (distributed Bragg reflection type) semiconductor laser 21a is changed to match the oscillation wavelength of the semiconductor laser 21a with the phase matching wavelength of the optical wavelength conversion element 22a and to control the generated higher harmonic wave P2 constant. As a result, the wavelength of the semiconductor laser remain constant and the stable operation is executed even if the environmental temp. changes.