General Electric Company

Tushar S Chande

Angel L Ortiz, Jr

Marshall Gordon Jones

John L August, Jr

Carl M Penney

Gregory Georgalas

An optical fiber coupler for coupling a high power laser beam delivered by an incoming fiber into multiple outgoing fibers is disclosed. The beam emitted from the incoming fiber is collimated and split into multiple split beam portions for injection into the respective multiple outgoing fibers. Each split beam portion is shaped for injection into its respective outgoing fiber in accordance with specific beam injection criteria.

Multi-fiber optical coupler for a high power laser beam

The temperature of a surface undergoing a radiation assisted thermally driven process is sensed by observation of the thermal emission from that surface and used to control the process. In a preferred embodiment, the blue edge of the thermal emission spectral distribution is detected to determine the surface temperature of a workpiece during a process such as laser-assisted chemical vapor deposition, and used to control this temperature. The temperature measuring system has means for focusing workpiece thermal emission and defining the field of view, a spectrometer to separate shorter wavelength light from other spectral components of the thermal emission, and a photon-counting system to detect the shorter wavelength light and generate a surface temperature signal. Systems to determine surface temperature at a spot and along a line have an optical prism to disperse the thermal emission into component wavelengths, and a multichannel photon-counting detector comprised of an intensified photodetector array.

Temperature measurement and control for photohermal processes

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.

Coupling device for high power laser beam transmitting optical fibers

An optical fiber output coupler for application to a power laser beam transmitting optical fiber is disclosed. The output coupler includes lenses for expanding the fiber delivered beam in order to enable minimization of the diameter of a focussed spot provided by a focussing lens of the coupler.

Optical fiber output coupler for a power laser

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.

Apparatus and method for optical fiber end positioning for laser

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. In a second illustrated embodiment, two mirrors are respectively mounted to scan the laser beam along 'x' and 'y' coordinate directions to direct the laser beam into fiber tip positioned proximate the respective focal points of four lenses.

Laser beam directing system

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.

Cooling rate determination apparatus for laser material processing

The invention is directed to lens apparatus for splitting a light beam into a plurality of beam portions which are focused. The invention finds utility in laser-materials processing systems in which the inventive lens apparatus is embodied in a fiber optic output coupler so that the fiber transmitted laser beam is split and focused at a plurality of predetermined process points on a workpiece.

Beam splitting fiber optic coupler

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.

Real-time laser beam diameter determination in a laser-materials

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.

Optical fiber holder

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.

Growing community of inventors

Schenectady, NY, United States of America

Tushar S Chande