Patent ID: 7817690

Claim:
A laser generator comprising: a generation means for pumping by a pumping light source a pumping medium to generate a fundamental-wave laser beam; an electric power supply for supplying current for exciting the pumping light source; an output sensor for measuring average output power or pulse energy of the fundamental-wave laser beam; a wavelength-conversion element, arranged on an optical path for the fundamental-wave laser beam, for converting the fundamental-wave laser beam into its higher-harmonic-wave laser beam; a current-command-setting means for setting and outputting a current-command-setting value as a current-command value for obtaining a desired laser-beam intensity; a memory unit for memorizing a determination value set to a value lower than a breakage threshold for average output power or pulse energy of the laser beam converted by the wavelength-conversion element; a current-command-calculation means for, when the current-command-setting value outputted by the current-command-setting means varies, outputting the current-command value while increasing the current-command value to the current-command-setting value by a predetermined variation amount, which is lower than a difference between the breakage threshold of the wavelength-conversion element and the determination value, at predetermined time intervals; a comparing means for comparing a measurement value measured by the output sensor and the determination value; and a switching means for switching; (a) when the measurement value is determined by the comparing means to be a value lower than the determination value, a current-command value transmitted to the electric power supply, to a first current-command value transmitted from the current-command-calculation means, (b) while when the measurement value is determined by the comparing means to be a value not lower than the determination value, the current-command value to a second current-command value by which the output power of the fundamental-wave laser beam becomes lower than the breakage threshold.