Patent ID: 8149885

Claim:
A fiber laser processing apparatus comprising: a fiber laser oscillator that includes an oscillation optical fiber having a core doped with a predetermined rare-earth element to excite the core of the oscillation optical fiber with pulsed excitation light to oscillate and output a pulsed fiber laser beam; a laser emitting unit that focuses and applies the fiber laser beam onto a process point of a processed object; a laser diode for generating the excitation light; an LD power source unit that supplies a pulsed LD drive current to the laser diode; a reference pulse setting unit that sets a desired reference pulse of the output of the fiber laser beam for laser processing; a reference signal generating unit that couples and sequentially generates a preceding pulse with a level having no substantial effect on the laser processing and the reference pulse on the time axis as a reference signal for power feedback control related to the output of the fiber laser beam to start the reference pulse rising from a level of the rear end of the preceding pulse; a laser output measuring unit for measuring the output of the fiber laser beam; a comparing unit that compares a laser output measurement value acquired from the laser output measuring unit with the reference signal supplied from the reference signal generating unit to output a comparison error thereof; and a control unit that controls the LD drive current through the LD power source unit such that the comparison error output from the comparing unit is set to zero.