Abstract: A fiber optic coupling device for coupling two optical fibers transmitting a high power laser beam is disclosed. In one embodiment, the device comprises a first lens to collimate the beam delivered by one of the optical fibers and a second lens to focus that collimated beam onto the end of the other fiber for injection therein and continued transmission of the power laser beam through the second fiber.

Abstract: Mechanical apparatus and method for positioning an optical fiber for injection with a laser beam is disclosed. The apparatus comprises a mechanical seat which is positioned to abut a first optical fiber which has been aligned by an optical alignment technique. Upon the need to replace the first fiber, the apparatus enables positioning of the mechanical seat at the same location so that a second fiber can be aligned in the same position as the first fiber without the need to employ an optical alignment technique.

Abstract: A system for directing successive beam pulses of a pulsed laser into different optical fibers, for transmission therethrough, is disclosed. The system comprises at least one lens, a plurality of optical fibers with the tips thereof positioned proximate a focal point of the lens, and at least one galvanometer driven mirror for directing a laser beam through the lens for focusing separately onto each fiber tip. The galvanometer, driven by computer generated position addresses, moves the mirror, between laser pulses, to predetermined positions each effective to direct the laser beam, through the lens, into one of the fiber tips for transmission via the fiber to a remote workstation location. In a first illustrated embodiment, a single mirror is mounted to direct the laser beam into fiber tips positioned substantially in the same plane and proximate the focal points of eight lenses.

Abstract: A laser materials processing system for computing a real time cooling rate experienced on a workpiece and responsively controlling the operation of a materials processing laser. An image of a point of laser beam-material interaction is transmitted via imaging optical fibers to ratio pyrometer apparatus which provides temperature proportional signals. The temperature signals are used to compute cooling rate.

Abstract: A break or leak in an optical fiber transmitting high power laser energy, at average power levels sufficient for material processing, is detected promptly and the laser beam delivery system shut down when the optical fiber begins to fail. Photo detectors monitor the laser power out of the fiber and injection power into the fiber, in particular the light intensities in the fiber input and output couplers. A difference in detector outputs, larger than a set threshold to account for inherent fiber losses, is an indication that a break or leak has occurred.

Abstract: A laser-materials processing system including means for determining an incident diameter of a laser beam at a point of laser beam-material interaction on a workpiece, is disclosed. A filtered image of the interaction point is transmitted, via an imaging fiber bundle, to a video camera. The analog video signal generated thereby is digitized and provided to a computer which evaluates the pixel magnitudes along a beam image diameter line to determine therefrom the incident laser beam diameter.

Abstract: An optical fiber holder includes a pair of flat, adjacent surfaces. Each of the surfaces includes a straight groove, the grooves opposing so as to form a passage shaped to engage an optical fiber in a snug fit. Means are provided for fastening the two surfaces together. The optical fiber holder is preferably constructed of material transparent to a laser beam at a predetermined wavelength, thereby making the optical fiber holder particularly adapted for use with a laser device generating such a laser beam.

Abstract: A system for injecting successive beam pulses of a pulsed power laser into optical fibers, for transmission therethrough, is disclosed. The system comprises four lens, four fiber groups with the tips thereof respectively proximate the focal points of the lenses, two galvanometer driven mirrors for directing the laser beam through one of the lenses for focusing onto a selected fiber tip, and control means to drive the galvanometers to reorient the two mirrors between laser beam pulses into successive pairs of predetermined positions effective to inject the successive beam pulses into selected fibers. Failure to reorient the mirrors before the succeeding beam pulse arrives results in laser shutdown. Means are provided for detecting a malfunction of the mirrors, fracture of a lens or a missed fiber injection and, in either case, shutting down the laser.

Abstract: High power laser energy for material processing is delivered via a high energy optical fiber to a remote output module carried by an industrial robot. A plural path optical system within the output module focuses the high-energy laser onto the material to be processed, and additionally transmits images for closed-loop robotic control through one or more fiber optic bundles. Thus vision and seam tracking for an industrial robot are integrated with a neodymium: yttrium-aluminum-garnet laser. To provide an interlock which guards against interruption of the high energy optical fiber, a laser transmission sensor is included within the remote module. A wide range of closed-loop laser materials processing operations can be performed, such as cutting, welding, drilling and heat treatment. The processing operations can be performed even on complex, three-dimensional parts.