Various light-scanning systems that can be used to perform rapid point-by-point illumination of a focal plane within a specimen are disclosed. The light-scanning systems can be incorporated in confocal microscopy instruments to create an excitation beam pivot axis that lies within an aperture at the back plate of an objective lens. The light-scanning systems receive a beam of excitation light from a light source and direct the excitation beam to pass through the pivot point in the aperture of the back plate of the objective lens while continuously scanning the focused excitation beam across a focal plane.