GB1276967A - Improvements in and relating to laser tubes - Google Patents

Abstract

1276967 Lasers COMPAGNIE INDUSTRIELLE DES LASERS 24 Nov 1970 [25 Nov 1969] 55798/70 Heading H1C A laser discharge tube comprises a capillary tube 21 located within and affixed to a tubular outer envelope 20, both capillary and envelope being made of materials having substantially the same coefficient of thermal expansion, and the envelope having resonator mirrors 24, 25 welded or otherwise secured to its ends. As shown in Fig. 1, the capillary tube may be of uniform cross-section and the envelope formed with portions 10, 11 of reduced cross-section to which the capillary is affixed by welding or adhesive. Alternatively, Fig. 2, one or both ends 40 of the capillary may be thickened and flared, so as to be directly affixed to an envelope of uniform outer diameter at the flared end, or an envelope of uniform outer diameter and varied internal diameter may support and secure a capillary of uniform cross-section at the regions of reduced internal diameter. The latter arrangement is used in Fig. 3, in which the region of reduced diameter may consist of individual protuberances 13, 14, the other capillary end being secured to and supported by an annular disc 31 made of the same material. In each case ports 29 are provided in the capillary, and discharge electrodes 26, 27 in the outer envelope. For mode suppression an afocal optical system comprising lenses 53, 56, Fig. 4, and an apertured disc 54 located at the common focal point is mounted on the end of the tubular envelope. As shown, each component of the system is mounted on a respective pair of elements 50, 57; 51, 58 and 52, 59 of an element stack. In a modification, Fig. 5, the system components are mounted on portions 17, 18 of reduced internal diameter in an extension of the tubular envelope, or on an annular disc 16 mounted within the extension.