Optical beam intensity control system with piezoelectric actuator

Abstract

An optical beam intensity control system with advanced accuracy, dynamic characteristics and extended functionality includes a piezoelectric actuator (3) rotating a light intensity changing element (5), a light intensity sensor (25), and a controller/generator (10). The actuator (3) comprises two piezoelectric rings (11) glued to an elastic ring-shaped disk (7) with an inner surface perforated by elongated slots (8) directed at an acute angle to the surface of a cylinder (6). A rotor (4) carrying the light intensity changing element is resiliently pressed against the outer surface of the cylinder. The piezoelectric deforms the disc in the radial direction, and torsional vibration is excited in the cylinder via the slots. Functionality is extended by adjusting the intensity of the beam (1) through an optical lens (21) attached to an outer part of the disc which is able to move together with the lens along the optical axis (24) when symmetrical bending deformations are generated in the disk along the optical axis.