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