Patent ID: 6206531
Filing Date: 2001-03-27
Classification: G02B,Y10S

Abstract:
A method of making a composite optical mirror substrate including a mirror surface having a shape comprising the steps of:selecting a reticulated foam skeleton which is less than approximately 10 percent dense and comprises ligaments, and forming said reticulated foam skeleton into a core for said mirror, a first face of said reticulated foam skeleton being formed into approximately the shape of said mirror surface;selecting a prefabricated dense material having a first surface and a second surface generally opposed to said first surface, said dense material having a first thermal expansion coefficient, and forming said first surface to approximately the shape of said mirror surface, and said second surface to approximately conform to the shape of said first face;rigidly mounting said second surface to said first face through a bonding material to form a workpiece;selecting a structural and optical coating material having a second thermal expansion coefficient, said first and second thermal expansion coefficients being within about 10 percent of each; andfully encapsulating said workpiece in a formed in situ layer of said coating material, said layer comprising an optical grade deposit on said mirror surface and encapsulating said bonding material and said ligaments throughout said reticulated foam skeleton, said mirror surface being on said first surface, whereby the thermal expansion coefficient, thermal conductivity, elastic modulus, specific stiffness, inertia loading parameter, thermal distortion parameter, and thermal stress parameter properties of said composite optical mirror substrate are substantially those of said coating material.