Abstract: A surface treating method and apparatus include operating a quasi-continuous wave fiber laser and pre-scan shaping the laser beam such that an instantaneous spot beam has predetermined geometrical dimensions, intensity profile, and power; operating a scanner at an optimal angular velocity and angular range to divide the pre-scan beam into at least one sub-beam deflected toward the surface being processed; guiding the sub-beam through a post-scan optical assembly to provide the spot beam with predetermined geometrical dimensions, power, and angular velocity and range, which are selected such that the instantaneous spot beam is dragged in a scan direction over a desired length at a desired scan velocity, which allow the treated surface to be exposed for a predetermined exposure duration and have a predetermined fluence distribution providing the treated surface with a quality comparable to that of the surface processed by an excimer laser or a burst-mode fiber laser.

Abstract: An additive manufacturing system may include a build surface and an optics assembly movable relative to the build surface. The optics assembly may direct laser energy from one or more laser energy sources toward the build surface to melt a portion of the build surface. The system may further comprise a gas flow head operatively coupled to the optics assembly and moveable relative to the build surface. The gas flow head may define a partially enclosed volume between the optics assembly and the build surface. The gas flow head may generate a non-uniform flow of gas through the gas flow head in a direction that is opposite a direction of motion of the optics assembly. A velocity of the gas flow may be sufficient to entrain particles ejected from the melted portion of the layer of material in order to remove the ejected particles from the partially enclosed volume.

Abstract: Systems and methods for additive manufacturing are generally described. In some embodiments, an additive manufacturing system may include at least one mechanical fixture in the form of a resilient member for accurately positioning one or more optical fibers without the use of adhesives. The resilient member may, in some embodiments, bias each optical fiber (or similarly, an endcap coupled to a distal end of an optical fiber) against an alignment fixture to maintain a desired position and/or orientation of the fiber or endcap. In some embodiments, an additive manufacturing system may include at least one stray light baffle for reducing the amount of stray light within the optical system.

Abstract: A surface treating method and apparatus include operating a quasi-continuous wave fiber laser and pre-scan shaping the laser beam such that an instantaneous spot beam has predetermined geometrical dimensions, intensity profile, and power; operating a scanner at an optimal angular velocity and angular range to divide the pre-scan beam into a plurality of sub-beams deflected towards the surface being processed; guiding the sub-beams through a post-scan optical assembly to provide the spot beam with predetermined geometrical dimensions, power, and angular velocity and range, which are selected such that the instantaneous spot beam is dragged in a scan direction over a desired length at a desired scan velocity, which allow the treated surface to be exposed for a predetermined exposure duration and have a predetermined fluence distribution providing the treated surface with a quality comparable to that of the surface processed by an excimer laser or a burst-mode fiber laser.

Abstract: A method of fiber laser processing of thin film deposited on a substrate includes providing a laser beam from at least one fiber laser which is guided through a beam-shaping unit onto the thin film. The beam-shaping optics is configured to shape the laser beam into a line beam which irradiates a first irradiated thin film area Ab on a surface of the thin film, with the irradiated thin film area Ab being a fraction of the thin film area Af. By continuously displacing the beam shaping optics and the film relative to one another in a first direction at a distance dy between sequential irradiations, a sequence of uniform irradiated thin film areas Ab are formed on the film surface defining thus a first elongated column. Thereafter the beam shaped optics and film are displaced relative to one another at a distance dx in a second direction transverse to the first direction with the distance dx being smaller than a length of the irradiated film area Ab.

Abstract: Optics assemblies and their methods of use in additive manufacturing systems are described. In some embodiments, an additive manufacturing system may include a build surface, a plurality of laser energy sources configured to produce a plurality of laser spots on the build surface, and an optics assembly configured to independently control a size of each of the plurality of laser spots and a spacing between the plurality of laser spots on the build surface. The optics assembly may include a plurality of lens arrays, where the plurality of lens arrays is configured to adjust a size of each of the plurality of laser spots on the build surface, and at least one lens. The at least one lens may also be configured to adjust a spacing between the plurality of laser spots on the build surface.

Abstract: A method of fiber laser processing of thin film deposited on a substrate includes providing a laser beam from at least one fiber laser which is guided through a beam-shaping unit onto the thin film. The beam-shaping optics is configured to shape the laser beam into a line beam which irradiates a first irradiated thin film area Ab on a surface of the thin film, with the irradiated thin film area Ab being a fraction of the thin film area Af. By continuously displacing the beam shaping optics and the film relative to one another in a first direction at a distance dy between sequential irradiations, a sequence of uniform irradiated thin film areas Ab are formed on the film surface defining thus a first elongated column. Thereafter the beam shaped optics and film are displaced relative to one another at a distance dx in a second direction transverse to the first direction with the distance dx being smaller than a length of the irradiated film area Ab.

Abstract: A surface treating method and apparatus include operating a quasi-continuous wave fiber laser and pre-scan shaping the laser beam such that an instantaneous spot beam has predetermined geometrical dimensions, intensity profile, and power; operating a scanner at an optimal angular velocity and angular range to divide the pre-scan beam into a plurality of sub-beams deflected towards the surface being processed; guiding the sub-beams through a post-scan optical assembly to provide the spot beam with predetermined geometrical dimensions, power, and angular velocity and range, which are selected such that the instantaneous spot beam is dragged in a scan direction over a desired length at a desired scan velocity, which allow the treated surface to be exposed for a predetermined exposure duration and have a predetermined fluence distribution providing the treated surface with a quality comparable to that of the surface processed by an excimer laser or a burst-mode fiber laser.

Abstract: A method of measuring morphological characteristics of a laser annealed film having a crystalline structure, which is defined by at least one row of side-to-side positioned grains each having a length (Lg), which is uniform for the grains, and width (Wg), wherein a length of the row (Lr) corresponds to a cumulative width Wg of the grains and creates a diffraction of various orders of diffraction, the method includes generating a monochromatic light; training the monochromatic light onto a surface of the laser annealed film at an angle varying in a range between 0° (incident) and grazing angles; and measuring variations of properties of the monochromatic light diffracted from the surface, thereby measuring the morphological characteristics of the laser annealed film along the length (Lr) of the one row.

Abstract: The inventive system for crystallizing an amorphous silicon (a-Si) film is configured with a quasi-continuous wave fiber laser source operative to emit a film irradiating pulsed beam. The fiber laser source is operative to emit a plurality of non-repetitive pulses incident on the a-Si. In particular, the fiber laser is operative to emit multiple discrete packets of film irradiating light at a burst repetition rate (BRR), and a plurality of pulses within each packet emitted at a pulse repetition rate (PRR) which is higher than the BRR. The pulse energy, pulse duration of each pulse and the PRR are controlled so that each packet has a desired packet temporal power profile (W/cm2) and packet energy sufficient to provide transformation of a-Si to polysilicon (p-Si) at each location of the film which is exposed to at least one packets.

Abstract: An optical output coupler includes an uncoated plano-concave lens having a planar side and a concave side. An optical axis of the plano-concave lens is tilted at or near a Brewster angle relative to a beam axis. A first optical element is configured to focus a beam of radiation emerging from the planar side of the plano-concave lens along a first axis that is perpendicular to the beam axis. The first optical element is disposed between the planar side of the plano-concave lens and a second optical element. The second optical element is configured to focus a beam of radiation emerging from the planar side of the plano-concave lens along a second axis that is perpendicular to the beam axis, wherein the second axis is different from the first axis.

Abstract: An optical output coupler includes an uncoated plano-concave lens having a planar side and a concave side. An optical axis of the plano-concave lens is tilted at or near a Brewster angle relative to a beam axis. A first optical element is configured to focus a beam of radiation emerging from the planar side of the plano-concave lens along a first axis that is perpendicular to the beam axis. The first optical element is disposed between the planar side of the plano-concave lens and a second optical element. The second optical element is configured to focus a beam of radiation emerging from the planar side of the plano-concave lens along a second axis that is perpendicular to the beam axis, wherein the second axis is different from the first axis.

Abstract: The inventive system for crystallizing an amorphous silicon (a-Si) film is configured with a quasi-continuous wave fiber laser source operative to emit a film irradiating pulsed beam. The fiber laser source is operative to emit a plurality of non-repetitive pulses incident on the a-Si. In particular, the fiber laser is operative to emit multiple discrete packets of film irradiating light at a burst repetition rate (BRR), and a plurality of pulses within each packet emitted at a pulse repetition rate (PRR) which is higher than the BRR. The pulse energy, pulse duration of each pulse and the PRR are controlled so that each packet has a desired packet temporal power profile (W/cm2) and packet energy sufficient to provide transformation of a-Si to polysilicon (p-Si) at each location of the film which is exposed to at least one packets.

Abstract: Continuous mass flow gas replenishment may be implemented in a gas lasing device, such as a gas laser or amplifier, by using a restrictive orifice to bleed one or more gases into a reservoir and/or discharge chamber of the gas laser or amplifier at a predefined mass flow rate. The mass flow rate is a function of the pressure drop across the restrictive orifice resulting from the pressure differential between the depleted gas and the source gas. Thus, gases may be added as needed such that the gas total pressure, as well as the constituent partial pressures, is maintained within a desired range throughout the laser or amplifier fill lifetime. The continuous mass flow gas replenishment may thus make up the lost partial pressure of reactive gases in gas lasing devices in a manner that is less complicated and is less expensive than other continuous flow methodologies.

Abstract: Laser machining systems and methods may include debris removal systems to remove debris generated by the machining process and/or outgassing or filtration systems to remove harmful gases and filter and recycle air within the system. The laser machining systems and methods may be used to scribe one or more lines in large flat workpieces such as solar panels. In particular, laser machining systems and methods may be used to scribe lines in thin film photovoltaic (PV) solar panels with accuracy, high speed and reduced cost.

Abstract: A pre-irradiation system and method may be used in a gas discharge lasing device to provide multiple ultraviolet (UV) pre-irradiation discharges per electrical feed-through into a gas discharge chamber of the lasing device. One or more high-voltage electrical feed-throughs are electrically connected to one or more high-voltage electrodes that provide multiple discharge paths to a current return electrode to allow multiple pre-irradiation discharges per feed-through in response to high-voltage pulses applied via the feed-through(s). The discharge paths may include spark gap discharge paths and/or tracking discharge paths across an insulator. In some embodiments, multiple discharge paths are formed between respective tracking locators on a high voltage electrode and/or a current return electrode. In other embodiments, multiple discharge paths are formed between respective discharge locations on a high voltage electrode surrounded by an insulator, which spark or track to a current return electrode.

Abstract: Multiple beamlet laser beam delivery systems and methods may be used in laser machining systems and methods to machine multiple regions on a workpiece simultaneously. One embodiment of a laser machining system and method may be used, for example, to scribe one or more lines in large flat workpieces such as solar panels. In particular, laser machining systems and methods may be used to scribe lines in thin film photovoltaic (PV) solar panels with accuracy, high speed and reduced cost. The multiple beam delivery systems may be movable to scribe multiple lines simultaneously in the workpiece.

Abstract: Systems and methods for laser scribing provide extended depth affectation into a substrate or workpiece by focusing a laser beam such that the beam passes into the workpiece using a waveguide, self-focusing effect to cause internal crystal damage along a channel extending into the workpiece. Different optical effects may be used to facilitate the waveguide, self-focusing effect, such as multi-photon absorption in the material of the workpiece, transparency of the material of the workpiece, and aberrations of the focused laser. The laser beam may have a wavelength, pulse duration, and pulse energy, for example, to provide transmission through the material and multi-photon absorption in the material. An aberrated, focused laser beam may also be used to provide a longitudinal spherical aberration range sufficient to extend the effective depth of field (DOF) into the workpiece.

Abstract: Laser machining systems and methods may include debris removal systems to remove debris generated by the machining process and/or outgassing or filtration systems to remove harmful gases and filter and recycle air within the system. The laser machining systems and methods may be used to scribe one or more lines in large flat workpieces such as solar panels. In particular, laser machining systems and methods may be used to scribe lines in thin film photovoltaic (PV) solar panels with accuracy, high speed and reduced cost.

Abstract: The inventive system for crystallizing an amorphous silicon (a-Si) film is configured with a quasi-continuous wave fiber laser source operative to emit a film irradiating pulsed beam. The fiber laser source is operative to emit a plurality of non-repetitive pulses incident on the a-Si. In particular, the fiber laser is operative to emit multiple discrete packets of film irradiating light at a burst repetition rate (BRR), and a plurality of pulses within each packet emitted at a pulse repetition rate (PRR) which is higher than the BRR. The pulse energy, pulse duration of each pulse and the PRR are controlled so that each packet has a desired packet temporal power profile (W/cm2) and packet energy sufficient to provide transformation of a-Si to polysilicon (p-Si) at each location of the film which is exposed to at least one packets.