Patent ID: 7436863

Claim:
A fiber laser beam processing apparatus for welding a work, the fiber laser beam processing apparatus comprising: an optical fiber for oscillation including: a core containing a luminous element; and a clad surrounding the core; a pumping unit to supply the core of the optical fiber for oscillation with an excitation beam, the pumping unit including: a laser diode that emits the excitation beam to optically pump the core of the optical fiber for oscillation; and an optical lens that condenses the excitation beam from the laser diode onto an end of the optical fiber for oscillation; a power source unit that turns on and drives the pumping unit to cause the optical fiber for oscillation to oscillate and output a laser beam having a predetermined wavelength, the power source unit including: a DC power source that provides an LD driving current to drive the laser diode; and a switching element connected between the DC power source and the laser diode to control the LD driving current; a laser beam irradiating unit that condenses and applies the laser beam generated by the optical fiber for oscillation onto a processing point on the work to be welded; a setting unit that sets a desired reference waveform for a laser power of the laser beam; a laser power measuring unit that measures the laser power of the laser beam oscillated and outputted by the optical fiber for oscillation; and a controlling unit that controls in real-time a switching of the switching element of the power source unit in a pulse width modulation scheme such that a laser power measured value obtained from the laser power measuring unit equals the reference waveform.