Optical beam intensity control system with piezoelectric actuator

Abstract

This invention is an optical beam intensity control system with a piezoelectric actuator, with advanced control accuracy, dynamic characteristics and extended functionality. The system consists of the piezo actuator rotating a light intensity changing element, a light intensity sensor and a controller-generator. Beam guiding mirrors and lenses can also be used. The piezoelectric actuator is the symmetrical bimorph type and consists of two thin-walled piezoelectric rings glued concentrically to a wider elastic thin-walled ring-shaped disk with an inner surface perforated with elongated slots where the slots are directed at an acute angle to the surface of the cylinder. The rotor with the light-intensity-changing element is resiliently pressed against the outer surface of the cylinder. The piezoelectric actuator rotates the light-intensity-changing element, deforming the disc in the radial direction. Functionality of the actuator is extended by the possibility of adjusting the beam flux density if the optical lens is attached to the outer part of the disc so that its optical axis coincides with the axis of symmetry of the disc. The piezoelectric actuator is able to move together with the lens along the optical axis when symmetrical bending deformations are created in the disk along the optical axis.