GB1256118A - Improvements relating to lasers - Google Patents

Abstract

1,256,118. Lasers. FERRANTI Ltd. 13 May, 1970 [31 May, 1969], No. 27706/69. Heading H1C. A laser resonator mirror is supported by a plastically deformable mount which allows initial alignment. Fig. 1 shows the mirror 17 at the end 16 of a tubular mount 13 connected to the base-plate 10 of a gas laser. The mount 13 has a circumferential groove 18 which allows the end 16 to be tilted relative to the laser optical axis. The adjustment is carried out using a jig 20, Fig. 2, which may be placed over the tubular mount and which carries screws 22 by which the grooved portion of the mount may be deformed until optimum alignment is achieved. The mount should be of a ductile material such as copper to minimize any backlash due to elastic deformation. Instead of a grooved portion, the mount 13, Fig. 3, may comprise a pair of coaxial tubes 14, 16, interconnected by a lead annulus 18 which may be deformed by removable screws 22, the outer tube forming the adjusting jig. The tube 16, which carries the mirror 17, may be the inner tube of the pair, Fig. 4 (not shown), which allows a smaller mirror to be used and protects the alignment against accidental blows. Any of the above mounts may be adhered directly on to the end of a gas laser tube or on to a Brewster window, Figs. 5-8 (not shown), the use of a Brewster window having the advantage that a gaseous infra-red absorber such as methane may be contained within the tubular mount. The mount may be used with solid, liquid or gaseous active media, and one would normally be used for each resonator mirror.