An apparatus and method for producing laser output light pulses in bursts
of pulses, at a selected pulse repetition rate, forming a laser output
light beam, separated by an off time is disclosed, which may comprise a
laser output light pulse beam parameter adjustment system, which may
comprise a laser output light pulse beam parameter error detector
providing a beam parameter error signal representative of the difference
between the beam parameter and a selected target value for the beam
parameter; a beam parameter adjustment mechanism; a beam parameter
adjustment mechanism controller providing a beam parameter adjustment
signal to the beam parameter adjustment mechanism based upon the value of
the beam parameter error signal; a slow transient compensator providing a
slow transient inversion signal modifying the beam parameter adjustment
signal based upon the value of the beam parameter error signal. The
apparatus and method may further comprise a beam parameter error scaling
mechanism providing a normalized beam parameter error signal determined
from the value of the beam parameter error signal; and the beam parameter
adjustment mechanism controller and the slow transient controller
providing, respectively, the beam parameter adjustment signal and the
slow transient inversion signal based upon the normalized beam parameter
error signal. The beam parameter adjustment mechanism controller may
provide the beam parameter adjustment signal based upon a controller
function that minimizes the average actual wavelength error or a windowed
standard deviation of the actual wavelength error.
