Patent GB-1269892-A (GB)
Title: Weapon system for the detection of and use against stationary or moving objects
Inventor: ERBEN KLAUS DIETER
IPC: H01S3/034
Filed: 1970-03-17
Abstract: 1,269,892. Lasers. MESSERSCHMITT-BOLKOW-BLOHM G.m.b.H. 17 March, 1970 [20 March, 1969 (4)], No. 12812/70. Heading H1C. [Also in Division G2] A weapons system comprises a laser structure of one or more CO 2  infra-red lasers, a reduced output from which is used for detection and identification of a target and the full output from which is used for target destruction. A single laser 100 having either a continuous or pulsed output in the 8 to 11 Á range is used in the system shown in Fig. 1, the active medium comprising CO 2  with He or N, the laser gas including carbon or oxygen isotopes. The laser output is normally at a low level and is directed and focused on the target by an optical system comprising a rotated toroidal or spherical mirror 14 and a parabolic mirror 11, and the radiation reflected from the target is directed on to a photo-detector 21 by the combination of focusing mirrors 12 and 13. The photodetector output is amplified at 22 and applied to a computer 40 which identifies the target, controls the focusing and direction of the mirror systems 11-14 by energizing three-co-ordinate positioning units 15, 16, 17, and in the case of a hostile target causes the laser 100 to switch from a low power output to a high power output. The laser may consist of a folded resonator, Fig. 2, which is terminated by mirrors 52 and includes further mirrors defining a folded optical path, each path section having individual anodes 54 and cathodes 56. Only certain sections of the path are pumped for low power output, all sections being excited when full power output is required. A gas curtain may be used in place of an optical window at the output end of the laser, Fig. 7, for separating the laser active gas from the external atmosphere, the curtain being provided by a tube 320, an extraction pump and tube 321, 322 and a pressure gas source 330. The curtain gas 325 has a high transparency such as nitrogen and is passed through combs 324 to prevent the formation of boundary layers by creating turbulence. Details of the electrodes are given, Fig. 5, each electrode consisting of concentric aluminium tubes 110, 112 spaced by webs 111 and supported by an adjustable conductive pin 114 and bar 116, insulation being effected by a sleeve 120 and insulating collar 121 and cooling by a jacket 117 with inlets and outlets 118, 119 for compressed air. The rotatable annular or spherical mirror 14, Fig. 1, is shown in detail in Fig. 6, the mirror consisting of a reflectivelycoated hollow body 220 mounted for rotation by gas bearing 228 and auxiliary starting roller bearing 226 on a shaft 230, the shaft being formed with concentric passages 231, 232, 233 and a central duct 234. A pressurized gas or liquid-gas flow passed from duct 234 to passage 232 by way of a nozzle 224 both cools the mirror and causes its rotation by reacting with internally mounted vanes 223. The same gas source is applied to the gas bearings 228 through passage 231. Laser amplifiers may be included in the laser structure; alternatively two CO 2  lasers are low powered and the other high powered may be respectively used for the purposes of detection and destruction.