Hermetically sealed optical mounting assembly

Abstract

An ultra-high, hermetically sealed optical mounting assembly for sealing a fragile optical element includes a lid portion defining a thin, bendable flange spring member to gradually and evenly apply a relatively low sealing load at a knife edge for grasping the optical element. A base portion defining a substantially non-bendable, mating flange surface defines a mating base, knife edge. A deformable metallic gasket is interposed between both knife edges and the optical element. An engineered gap between the opposed lid and base flanges and a second, optional gap between the lid and base nearest the window are used to control the amount of spring forces and the amount of compression on the window. A modest sealing pressure applied to the outer edge of the lid flange bends the flange towards the base to spring the remainder of the lid outwardly from the mating base thereby causing the sealing forces to be gradually transferred through the outwardly bending central portion of the lid to the knife edges which then gradually and evenly press against the metallic gaskets to seal the window. The bent lid flange is welded to the base forming a hermetic joint around the entire periphery of the optical mounting assembly. In other aspects, the spring mechanism is an angled spring member integral with the contact areas and a vacuum guard may connect with the sealed cavity formed between the ultra high vacuum seal around the window and the hermetic seal around the flange.