Optical attenuator providing controlled attenuation
AssigneeThomson-CSF
Inventord'Auria Luigi
Life of this patent
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Abstract
The real attenuation produced by the optical attenuator is determined by means of photodetectors which carry out continuous measurement of the intensity of an auxiliary beam before and after it passes through the attenuator element. Signals which are emitted by the photodetectors and are proportional to the intensity received are transmitted to an electronic processing system which computes and displays the attenuation in decibels.
Claims16
An optical attenuator system providing controlled attenuation and comprising an attenuator element interposed on the path of a principle light beam, and a control input for adjusting the attenuation, wherein the attenuation produced by the attenuator element is continuously detected by an auxiliary optical system which is optically coupled to said attenuator element, wherein said auxiliary optical comprises an auxiliary light source and means for forming an auxiliary beam and measuring the intensity of said auxiliary beam both upstream and downstream of the attenuator element, and wherein an electronic processing system receives the signals delivered by said auxiliary optical system in order to generate an attenuation control signal.
Dependencies are inferred from the claim text.