TABLE 1.

Focusing deviations with different VSs (mm).

	Deviation in each direction
Virtual source	x	Y	z
(0.0, 0.0, 0.0)	(1.0, 4.0, 25)	(0, 4.0, 0)	(0.5, 16.0, 3.0)
(10.0, 0.0, −10.0)	(0.5, 4.0, 12.5)	(0, 4.5, 0)	(0.5, 17.0, 3.0)
(−10.0, 0.0, −10.0)	(0, 3.5, 0)	(0, 4.5, 0)	(0.5, 16.5, 6.7)
(0.0, 0.0, −10.0)	(0, 3.0, 0)	(0, 3.5, 0)	(0.5, 16.5, 3.1)
(10.0, 10.0, 0.0)	(1.0, 3.5, 14.3)	(1.0, 4.0, 12.5)	(0.5, 14.5, 3.5)
(10.0, −10.0, 0.0)	(1.0, 3.5, 14.3)	(1.0, 4.0, 12.5)	(0.5, 14.5, 3.5)

Format of deviations in each direction is as follows: focusing-position deviation (mm), main-lobe width (mm), deviation ratio (%).