Method and apparatus for measuring the relative intensity of the beams emanating from a single laser
AssigneeThe United States of America as represented by the Secretary of the Army
InventorsBenjamin L. Bluford, Jr., Alexander G. Mondrick, Jr., Milan Schwartz
Life of this patent
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Abstract
The laser beam to be measured is focussed onto a photographic film to rec the beam pattern. A second laser beam is then used to measure the displacement of the side lobes from the main beam. An apertured metal plate is then substituted for the film and, by the use of a beam deflector and a calorimeter, the intensity of the main beam alone is measured. Using the beam displacement data previously recorded, the metal plate is then moved to co-incide with one of the side lobes and the intensity of the side lobe recorded. This procedure is repeated for all remaining side lobes.
Claims6
Apparatus for determining the comparative intensities of the main and auxiliary output beams from an energized first laser, which comprises:
- a film for revealing the spatial distribution of said output beams incident thereupon;
- a metal plate substitutable for said film containing an aperture through which one only of said output beams can pass at a given time;
- a support for holding first said film and next said apertured plate in the path of the output beams;
- means for moving said support and the supported plate along two orthogonal axes in a plane normal to the path of said output beams;
- means for measuring the energy content of an incident laser beam;
- and
- means positioned downstream of said support for deflecting successively given ones of said output beams passing through the aperture in said metal plate into said energy measuring means.
A method of determining the comparative intensities of the main and auxiliary output beams from an energized first laser, which comprises the steps of:
- (a) determining the location of each of the discrete output beams by directing said beams upon the surface of a film to provide corresponding visible regions on the film, thereby to record the spatial distribution of said output beams;
- (b) selectively blocking all but one of the output beams whose position has been determined;
- (c) measuring the energy in said non-blocked output beam;
- and then
- (d) repeating steps (b) and (c) until the power of all output laser beam has been measured.
Dependencies are inferred from the claim text.