Abstract: A flashlamp pumped laser is controlled to emit a series of narrow pulse width laser pulses in quick succession. A control circuit associated with the flashlamp receives firing signals of limited pulse duration and serves to ignite and extinguish the flashlamp in accordance with the leading and trailing edges of a single firing signal pulse. The laser generates a coherent light pulse corresponding to the pumping flashlamp pulse. The flashlamp control circuit includes a main capacitor which stores electric charge sufficient to provide current to the flashlamp for several pulses in succession. The circuit also includes a trigger capacitor which supplies current through a transformer coupled to the flashlamp to initiate current conduction therein.

Abstract: A beam distributor apparatus employing an eccentrically mounted retroreflector prism is driven to revolve about a central axis by a motor/encoder to direct an input beam to a plurality of optical fibers in sequence. The retroreflector prism possesses the property of reflecting a beam in a directional parallel to the incident beam but displaced laterally therefrom. In one arrangement, a synchronously triggered laser is used as the light source. In a second embodiment, a non-laser light source is employed with a shutter coupled to be triggered in synchronism with the position of the rotating prism relative to the output optical fibers.

Abstract: The optical window is useful in laser-initiated explosive devices. It includes a solid transparent block of high temperature-resistant material such as glass, quartz, corundum, cubic zirconia or the like having two opposed light input and light output surfaces, one or both of which bear ablative mirror coatings of metal or the like, preferably aluminum, silver or gold, which can be vaporized by a laser beam. Preferably, the coatings are covered by a protective ablative film which resists scratching or the like. Such may be, for example, silicon monoxide. The coatings reflect incident light so as to prevent inadvertent initiation of explosive situated behind or downstream of the window in an explosive device. Preferably, the block is cylindrical with a curved light-focusing input surface which reduces the intensity which the laser beam trained through the window has to have in order to vaporize the mirror coatings and set off the explosive.

Abstract: The explosive initiator features an angled fiber optic adapter connected thereto. The initiator includes an elongated tubular cartridge with a longitudinal passageway having input and output ends and an explosive disposed therein downstream of a transparent sealing window and upstream of an output closure. The adapter has an elongated passageway therethrough with input and output ends and divided into a first portion at an angle of preferably 90 degrees from the longitudinal axis of the cartridge and a second portion in line with the cartridge. A mirror lens is positioned in the adapter passageway at the intersection of the two portions for reflecting a light beam from an optical fiber in the inlet end of the adapter to the cartridge passageway and focusing the light beam on the window. Preferably the second portion of the adapter is rotatably mounted to the cartridge.

Abstract: The improved focusing mirror lens reduces the ellipticity of the output beam of a laser diode or the like light source and corrects astigmatism of the beam so that beam light can be focused to a fine point. The lens has a monolithic, transparent, preferably cylindrical lens body of glass or the like, upon the opposite entrance and exit ends of which are coated focusing mirrors. At least one of the mirrors, and preferably both, has the configuration of a segment of a circular cylinder. The other mirror may have the configuration of a segment of a circular cylinder or of a sphere. The axes of the mirrors, when both are segments of a cylinder, are perpendicular to each other. Each of the mirrors has a light-transmitting unmirrored pupil aligned along the longitudinal axis of the lens body.

Abstract: The novel optical explosive initiator employs a window of a new type. The window hermetically seals the initiator explosive and is a transparent preferably monolithic block or cylinder of glass or the like solid material having a mirrored convex entrance end in the configuration of a segment of a spheroid, paraboloid, ellipsoid or hyperboloid and having an unmirrored opening therethrough along the longitudinal axis of the cylinder. The opposite exit end of the cylinder is mirrored and is perpendicular to the cylinder longitudinal axis and is at least nearly flat, preferably entirely flat. It includes an unmirrored opening along the longitudinal axis of the cylinder. An optical fiber transmitting light, such a laser light, can be positioned adjacent to the entrance opening.

Abstract: The method seals optical windows in explosive initiators so that the resulting seal remains undamaged by exposure to about - 320.degree.-840.degree. F. and pressures up to 26000 psi. The method includes disposing a solid body optical window of quartz or silica glass or the like in a passageway in a wall of an explosive initiator body of metal, ceramic or the like. The optical window is dimensioned relative to the passageway so that an annular space is provided between the outer periphery of the optical window and the passageway wall. This annular space is filled with solder glass, in powdered or solid body or slurry form. Preferably, the solder glass is a ring which closely fits around the optical window. The resulting sub-assembly preferably abuts a shelf in the passageway formed between two contiguous portions of the passageway with different diameters, the sub-assembly being in the larger portion.