a second location shown with a phantom line relative to the work surface 908 thus the laser beam 906 forms a second spot size 904 shown with a phantom line at the work surface 908 the scan lens 914 may include multiple optical elements and may be large and heavy as compared to the weak moving lens 910 thus the scan lens 914 may be difficult to move at high velocities the weak moving lens 910 on the other hand may be approximately as small as the diameter of the input laser beam 906 and may include only one or two optical elements thus the weak moving lens 910 is substantially lighter than the scan lens 914 and is much easier to move at high velocities fig1 is a block diagram of a system 1000 for rapidly manipulating a spot size 904 of a laser beam 906 at a work surface 908 according to another embodiment the system 1000 includes an adaptive lens or mirror 1010 beam steering optics 912 and a scan lens 914 in an optical path of the input laser beam 906 the surface curvature of the adaptive lens or mirror 1010 may be externally manipulated e g using piezo actuators to change the system 39 s focal length for example fig1 shows the surface of the adaptive lens or mirror 1010 in a first position shown with a solid line and in a second position shown with a phantom line when the surface of the adaptive lens or mirror 1010 is in the.