Patent ID: 7646794

Claim:
A laser apparatus comprising: a first laser oscillator for oscillating a pulsed laser light; a pulse power source for generating a current signal and a mask signal for masking a fluctuation component included in the current signal, and for supplying the current signal whose fluctuation component is masked by the mask signal to the first laser oscillator; a second laser oscillator for oscillating a continuous wave laser light; a first optical system that generates a superimposed laser light by superimposing the pulsed laser light with the continuous wave laser light, and for focusing the superimposed laser light; a second optical system for shaping a focus spot of the pulsed laser light to a circular shape; and a third optical system for shaping a focus spot of the continuous wave laser light to a rhombic streamlined shape, wherein the first optical system is for forming a focus spot for the superimposed laser light in which the circular-shaped focus spot for the pulsed laser light is included in the rhombic-streamlined-shaped focus spot for the continuous wave laser light; the pulse power source comprising: a chopper/inverter power source for generating the current signal; a switch element for receiving the current signal from the chopper/inverter power source and supplying the current signal to the first laser oscillator; and a mask circuit for generating the mask signal and, by the switch element, suspending supplying of the current signal to the first laser oscillator.