Abstract: A method of providing secure tactical communications between a submerged submarine and an airborne platform using a pulse-modulated blue-green laser beam. During an initial acquisition mode, the airborne transceiver sends out a downlink laser beam to the ocean surface and below using a predetermined IFF code to identify the transceiver to the submarine. In the preferred embodiment the transmit optics spread the beam out into an elongated elliptically-shaped pattern to maximize coverage of the search area. When the downlink beam energy is within range of the submarine, an optical receiver on the submarine detects the beam, filters out the background light with a very narrow-band filter, and converts the light pulses to equivalent electrical pulses. A signal processor in the submarine receiver decodes the electrical pulses and verifies the IFF code to prevent the submarine from responding to a laser beam from an unfriendly source.

Abstract: A laser pumping assembly with a housing having a removable heat resistant glass liner or shell enclosing a pump and a laser rod comprises removable glass or quartz plates over opposite ends of the shell together with a heat absorbing shim between each end plate and an adjacent heat conductive support plate attached to the housing. The outside surface of each end plate is coated with a dielectric layer which reflects the desired wavelength of pump lamp radiation inwardly of the shell toward the laser rod and transmits undesired wavelengths to the adjacent shim. The shims are held tightly against the end plates and pass heat from the unreflected pump lamp radiation to the respective support plates for dissipation in the cooling system.

Abstract: An improved conductively cooled laser pumping assembly comprises a metallic housing having an elliptically shaped bore in which a pump lamp and laser rod are supported along the respective focal axes of the bore. The laser rod is mounted on the tapered end of a conductively cooled metal body by resilient strap means at opposite ends of the rod and with a relatively low melting temperature solder between the body and the rod to enhance thermal contact with the rod and to accommodate the different thermal expansions of the rod and body, thereby minimizing rod strain. The elliptical bore is coated with a heat absorbing substance and contains a similarly shaped one-piece snugly fitting removable glass liner or shell.