Plural pass vision system
AssigneeThe United States of America as represented by the Secretary of the Army
InventorRobert V. Goedert
Life of this patent
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Abstract
Disclosed herein is an optical system which allows light below a given flce to pass but which blocks light above the given fluence so that a human viewer using the system is not harmed by high energy lasers directed at the system. The optical system concentrates incoming light at a first focal zone in a NLASM, or nonlinear absorbing or scattering material. During a time delay, the system reconcentrates the light at a second focal zone to which the plasma zone has had time to expand. The character and number of light concentrations in the NLASM can be varied to protect the human viewer from a wider range of harmful light fluences.
Claims12
An optical system for selectively passing light below a given fluence while blocking light above the given fluence, the system comprising:
- a NLASM;
- a first focal zone within the NLASM;
- a first receiving means for concentrating within the first focal zone parallel light rays entering the system;
- a second focal zone within the NLSAM;
- repassing means for redirecting and refocussing light rays leaving the first focal zone into the second focal zone;
- a second receiving means optically downstream of the repassing means for receiving exiting light rays that have passed through the second focal zone, the second receiving means placing the exiting light rays in mutual parallel relation.
Dependencies are inferred from the claim text.