Abstract: Laser processing methods, systems and apparatus having a super-modulating power supply or pumping subsystem and high beam quality (i.e., brightness) are disclosed. The methods, systems and apparatus have significant benefits, improved operation characteristics and material processing capability over currently available methods, systems and apparatus. In at least one embodiment, the beam quality of a high power solid state laser is improved in the presence of thermal lensing. High power laser cutting, scribing, and welding results are improved with a combination of modulation and high beam quality while providing for improved processing speeds.

Abstract: A method and system for laser welding non-circular or non-concentric parts, such as catalytic converter components. The present invention provides a method (and corresponding system for carrying out the method), comprising: providing a part having sections to be welded together; rotating the part on a constant speed rotary; generating a laser beam; directing the laser beam onto a surface of the part to weld the sections of the part together; and controlling the laser beam such that an angle of incidence of the laser beam on the surface of the part remains constant, the laser beam remains in focus on the surface of the part, and the laser beam moves at a constant surface speed along the surface of the part as the part is rotated on the constant speed rotary.

Abstract: Methods and systems for laser-based processing of materials are disclosed wherein a scalable laser architecture, based on planar waveguide technology, provides for pulsed laser micromachining applications while supporting higher average power applications like laser welding and cutting. Various embodiments relate to improvements in planar waveguide technology which provide for stable operation at high powers with a reduction in spurious outputs and thermal effects. At least one embodiment provides for micromachining with pulsewidths in the range of femtoseconds to nanoseconds. In another embodiment, 100W or greater average output power operation is provided for with a diode-pumped, planar waveguide architecture.

Abstract: A solid state laser, includes laser rod tubes (10, 117) crimped onto each end of a laser rod (15, 121) with PTFE seal rings (25, 118) compressed between the laser rod and the laser rod tube. The compressed seal rings provide an improved leak tight seal in a laser pumping chamber. Each laser rod tube (10) provides a mounting and holding area (20) for supporting the laser rod ends therein while protecting and sealing the end faces of the laser rod. A swaging tool (40) and method for swaging the laser rod tube (10) onto the laser rod (15) to provide a compression fit are provided. The compression seal and swaging method are usable in a variety of leak tight sealing applications.

Abstract: For protecting a fibre optic conductor assembly from errant radiant energy, this invention provides a body mounted adjacent to an optical fibre so as to provide an alternate path for radiant energy adjacent to the path defined by the optical fibre, the body having a distal end which is angled so that radiant energy reaching the distal end undergoes total-internal-reflection so as to be re-directed out of the body and away from the optical fibre.

Abstract: A connector for an optical fibre comprises a body which receives a male connector having a conduit termination and a lens-fibre cell. A rotatable sleeve on the body serves via a slipper to move a first floating ball radially inward to clamp the lens-fibre cell against a V-bar or other support and, simultaneously, to move a plurality of angularly spaced floating balls to axially clamp the conduit termination. A ratchet is provided to avoid disconnection other than in a controlled manner by release of a locking collar.

Abstract: When a laser beam interacts with a workpiece to be welded by the beam, a plume of optical radiation is generated. An apparatus and method is disclosed in which radiation from the plume is received back through a beam delivery path comprising optical elements (L1,L2) having chromatic aberration. This alters the focus of different spectral bands of the plume radiation and a discriminating aperture is formed by a face of an optical fibre (3). After passing through the fibre, the plume radiation is separated from any laser radiation and the respective powers of the different spectral bands are measured (5). By subtraction, an error signal is obtained which is used to control the focus of the laser beam.

Abstract: A laser system is described in which two laser elements are configured as an oscillator and an amplifier in a common optical pumping section. Oscillator element is in a resonator and a divergent oscillator output beam is steered by a steering arrangement back to the amplifier element. The divergence of the beam from the resonator is adjusted, by moving output coupler element or selecting particular curvatures of resonator mirrors for example, to match the thermal lensing power of the amplifier element so that a substantially collimated output beam is produced.

Abstract: A method and apparatus for optimising the output of a multi-element laser, typically a multi-rod laser is disclosed, the method comprising obtaining a graph of power output against power input for the resonator, selecting an instability point where the output dips, measuring the power output at that point, selectively altering the gains of each of the power supply means supplying each of the laser elements, and selecting an optimum combination of gain values to provide maximum output power at that point.

Abstract: A laser system comprises an optical head, a power supply and a computer for controlling the power supply. The optical head comprises a pair of mirrors and four pumping sections. Each pumping section comprises a pair of gas discharge lamps pumping an Nd:YAG laser element. The power supply provides the lamps with alternating current at 25 kHz so that the laser system produces a continuous, modulated or pulsed output light beam. The power supply comprises three boost converters connected in parallel for converting three phase mains supply to direct current and four DC-AC converters. Each DC-AC converter converts the DC output from the boost converters to an AC supply for the lamps of a respective one of the pumping sections.

Abstract: A laser system comprises a laser (500) whose output beam is delivered to a workpiece (504) by an optical fiber (502). A transducer (506) detects the power of light propagating in the cladding layer of fiber (502) at a position near its input end. The transducer (506) also strips out the light travelling in the cladding layer. The output of transducer (506) is divided by the output of a transducer (507), which detects the power of the output beam of laser (500), to produce a signal indicative of misalignment between the laser beam and the core of fiber (502) at the input face. A transducer (505) comprises a second fiber (508) optically coupled with the cladding layer of fiber (502). Light emitted from the ends of fiber (508) is detected by a pair of detectors (509, 510), whose outputs are indicated on displays (512, 514). Display (512) provides information on the integrity of transmissions of the laser beam through fiber (502).

Abstract: Various examples of an optically pumped laser are described. In each example, a laser member formed from active laser material is located in an optical cavity and a source of pumping light is arranged so that pumping light passes into the laser member through a side surface. A deflecting means is provided which ensures that the pumping light makes an initial pass followed by at least one, and preferably at least two, further passes across the laser member. In the further passes, the pumping light has a substantial component long the optical axis. Consequently, a relatively long absorption path for the pumping light is achieved. In one example, the laser member is an Nd:YAG bar (20), the pumping light source is an array (23) of laser diodes, and the deflecting means takes the form of a series of facets (27) formed along a side of the bar (20). In another example, the deflecting means is a diffraction grating.

Abstract: A laser beam combining unit combines the output beams of a plurality of high power lasers after the beams have been transmitted along, for example, three optical fibres. The beam combining unit includes a holder arrangement for receiving the ends of the optical fibres, three collimating lenses, and a single focusing lens. The ends of the three optical fibres are located substantially in a common plane and circularly spaced at 120.degree. intervals. The three collimating lenses are also located substantially in a common plane and their axes are circularly spaced at 120.degree. intervals. Each of the collimating lenses is aligned with one of the optical fibres. The laser beams are directed by the collimating lenses, as collimated beams, onto the focusing lens with axes of the individual beams parallel to each other. The beams are focused by the focusing lens to a common point for performing a material processing operation.

Abstract: In order to compensate for the thermally induced lens in the active element of an optical stage of a laser, the optical stage is provided with a telescope. The telescope comprises first and second lens arrangements. The first lens arrangement is located so that thermally induced lens is located at one of its focal planes. The position of the second lens arrangement is adjusted so as to compensate for variations in the power of flashlamps which pump the active element. In one embodiment, the laser has an oscillator stage and an amplifier stage. The telescope is placed after the oscillator stage and comprises two convex lenses.