{HEAD ~ A further object} is to provide a spot wobble defocusing scheme for affecting {TAIL ~ the beam} vertically while not affecting the beam horizontally 
{ HEAD ~ A further object } is to provide a spot wobble defocusing scheme for affecting { TAIL ~ the beam } vertically while not affecting the beam horizontally
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH