Abstract: A computer controlled apparatus is disclosed for controlling a sequence of machine steps utilizing a laser beam whose power level is adjusted in accordance with its parameters as a function of a measurement of the power level of the generated laser beam. The laser apparatus includes a laser source or rod for emitting a laser beam and means in the illustrative form of a laser lens assembly for focusing and directing the laser beam onto the work piece. The laser source is associated with excitation means in the form of lamps for pulse driving or exciting the laser rod to emit a like sequence of laser pulses, whose parameters, e.g. pulse width and frequency, are selectively varied and controlled. The power level of the laser beam is calibrated by first measuring the power level of the laser beam as directed onto the laser piece, and then by using the measurement of laser power to calibrate or to adjust the degree of lamp excitation.