Hermetically sealed apparatus and method for maintaining crystals at a

Abstract

An apparatus for maintaining a crystal at a precisely controlled operating temperature over extended periods of time without significant thermal degradation of the crystal. The apparatus has thermally conducting walls. The walls define an inner hermetically sealed chamber for the crystal. Input and output windows are hermetically sealed to the input and output ends of the chamber. The inner surfaces of these windows are maintained at the operating temperature of the crystal to prevent fogging of the windows. Flexible thermal conducting layers are used between the crystal surfaces and the walls of the chamber to achieve uniform and continuous thermal contact therebetween, without mechanical stress to the crystal. The structure provides fast thermal response, controlled temperature in the crystal interaction region and stability of operation over extended periods of time. In one preferred embodiment, the crystal is held in suspended position within the chamber between a pair of spring-loaded plungers. Other embodiments and options are also disclosed.