Means and method for reducing the amount of light irradiating an object

摘要

A nonlinear optical medium wherein the optical index of refraction is a function of the intensity of light irradiating the medium, is employed in various devices to affect at least a portion of an incoming light beam by refracting or reflecting that portion of the light and thereby reduce the amount of light falling on an object. The nonlinear optical medium is employed in a resonator optical bistable device, in a self-bending approach and in a self-defocusing approach to provide the protective function. The spatial profile of light intensity of the incoming light can be shaped prior to the incoming light irradiating the nonlinear medium or the nonlinear medium itself can be shaped to provide the path altering function. A laser hardened device with ultra fast switching time, a large dynamic range and passive operation is a preferred application of the present invention.