USA As Represented by Secretary of the Navy

William C Fitzgerald

Edwin M Allen

Steven A Sievert

Henry F Blazek

Marino S Melsted

Eugene C Foust

George Turner

Max L Moffitt

An optic surface apparatus capable of handling aspheric surfaces uses dir measurement of the blur circle of the image created by the test surface. Direct measurement of the blur circle is obtained by providing a collimated light beam which includes the test surface in its optical path to an ultimate focal point. The focal point is occupied by an apertured screen with apertures of varying diameter. A light detector is placed behind the apertured screen to measure the intensity of light as a function of aperture size. The apertured screen and detector are mounted on a three-axis translator. For apertures less than the effective diameter of the blur circle, less than 100% light is received by the detector. For apertures equal to or greater than the effective diameter of the blur circle, 100% of the light reaches the light detector. A folding mirror is used in the optical path to permit the device to be physically compact. Different wavelengths of test energy may be employed provided that appropriate adjustments are made to the corrector lens and detector choice.

Asperic surface test fixture

A low reflectance reticle immersed in optical cement between transparent strates. A copper reticle is vacuum deposited upon one transparent substrate and chemically treated to produce anti-reflectance properties. The reticle and substrate to which it is attached are then cemented with optical cement to a second transparent substrate to immerse the anti-reflectance reticle between tranparent substrates in optical cement. The immersed reticle thus formed has superior anti-reflection properties and is protected from mechanical damage by its immersed location. Immersed reticles may be installed between elements of a compound lens if desired.

Immersed reticle

A wide angle radiant energy detection apparatus arranged as a catadioptric assegrainian telescope having a plane secondary mirror is disclosed which utilizes a correcting lens as a structural support for the secondary mirror to reduce losses caused by mirror support structure vignetting. Angular resolution at wide field angles is increased by lenses which reduce oblique spherical aberation, spherical aberation, and coma, and by the more uniform energy distribution across the image field caused by the lack of vignetting optical support structure.

Wide angle laser seeker

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Ridgecrest, CA, United States of America

William C Fitzgerald