Large aperture, very high temperature, hermetically sealed optical

Abstract

The invention provides a metal vapor Raman cell structure for laser wavelength conversion and a method for mounting a sapphire window onto a metal tube having a known outside diameter in the manufacture of the aforesaid Raman cell. According to the method of this invention, a sapphire window and a metal tube having a dissimilar coefficient of thermal expansion are mounted and sealed together. The method of sealing the sapphire window onto the metal tube comprises the steps of: (1) cutting a narrow circular groove in one face of the sapphire window; (2) mounting the metal tube into the seat defined by the groove cut into the sapphire window; and (3) disposing a sealing material between the outer face of the seat defined by the groove and the metal tube disposed therein. According to this technique, the sealing material disposed in the groove is placed under compression during the operation of the vapor Raman cell so constructed. The narrow circular groove cut into the sapphire window defines a seat having a bottom portion, an inner face, and an outer face. This seat is adapted to receive therein the metal tube of a known outside diameter. Once the metal tube is mounted into the seat defined by the groove, the sealing material is disposed between the outer face of the seat and the metal tube disposed therein.