Abstract: A method of delivering a beam of laser-radiation to a workpiece for processing the workpiece comprises transmitting the beam twice through an inactive acousto-optic modulator (AOM) crystal in opposite zero-order directions of the AOM at separate locations on the AOM crystal, before delivering the beam to the workpiece. When laser-radiation is to be blocked from reaching the workpiece, the AOM is activated.

Abstract: An aluminum covered with an anodically formed aluminum oxide layer is marked by repeated bursts of two or more individual laser pulses. The intensity of the individual pulses in the bursts is kept below a level experimentally determined to compromise the integrity of the aluminum oxide layer. The collective fluence in a burst is sufficient to mark the aluminum, but not sufficient to compromise the integrity of the oxide layer.

Abstract: In a flow cytometer, an objective lens for focusing an input laser-radiation beam including at least four different laser-radiation wavelengths in a common plane includes only three singlet lens-elements. Two of the elements are cylindrical elements arranged as a cylindrical telescope for shaping and reducing the size of the input laser-beam. The third element is a spherical element arranged to focus the reduced size beam in the common plane. In one example, all three elements are made from the same optical material.

Abstract: A diode-laser assembly having an electrically isolated diode-laser bar on a cooled base-element is disclosed. The diode-laser bar is electrically isolated from the base-element and electrically isolated from any coolant water, thereby eliminating the need for de-ionized water and mitigating corrosion due to galvanic action. Multiple such diode-laser assemblies are stackable, with small bar-to-bar pitch, enabling a high-current and high-brightness diode-laser stack.

Abstract: Laser-drilling apparatus includes a gas-discharge for laser emitting laser-radiation pulses, and two acousto-optic modulators (AOMs). The laser radiation pulses are characterized as having two temporal central portions between temporal leading and trailing edge portions. The AOMs are arranged to spatially separate the central temporal portions of the pulses from each other and from the leading and trailing edge portions of the pulses.

Abstract: Systems and methods for material singulation. According to some embodiments, methods for material singulation may include applying a first laser output to the material, the first laser output causing a modification of a material property of the material when exposed to the first laser output; and applying a second laser output to the material that was exposed to the first laser output to cause singulation of the material in such a way that surfaces created by the singulation of the material are substantially free from defects.

Abstract: An intra-cavity frequency-tripled OPS laser has a laser-resonator including two optically nonlinear crystals arranged for type-I frequency conversion. One of the crystals generates horizontally polarized second-harmonic radiation from vertically plane-polarized fundamental-wavelength radiation circulating in the laser-resonator. A birefringent filter is located between the optically nonlinear crystals. The birefringent filter selects the fundamental-wavelength, establishes the vertical polarization-orientation, and selectively rotates the polarization-orientation of the second-harmonic radiation from horizontal to vertical. The vertically polarized fundamental and second-harmonic radiations are type-I sum-frequency mixed by the other optically nonlinear crystal.

Abstract: A housing for an optically pumped semiconductor (OPS) laser resonator is terminated at one end thereof by an OPS-chip. The laser resonator is assembled on a platform with the OPS-chip at one end of the platform. The platform is fixedly attached to a baseplate at the OPS-chip end of the platform. The remainder of the platform extends over the baseplate with a gap between the platform and the baseplate. A pump-laser is mounted directly on the baseplate and delivers pump radiation to the OPS-chip.

Abstract: A mirror is used to form a beam of laser-radiation having a uniform intensity distribution from a beam of laser-radiation having a non-uniform intensity distribution. The mirror has a reflective surface that has a compound shape, which is two inclined surfaces joined by a rounded apex. The compound-mirror is achromatic and can form a uniform intensity distribution from a polychromatic beam of laser-radiation. The uniform intensity distribution may be an isotropic distribution or a flat-top distribution in a plane. The non-uniform intensity distribution may be a Gaussian distribution from a laser source.

Abstract: A diode-laser bar assembly comprises a diode-laser bar mounted onto a cooler by way of an electrically-insulating submount. A laminated connector is provided that includes two electrically-conducting sheets bonded to opposite sides on an electrically-insulating sheet. An electrical insulator is located between the laminated connector and the cooler. One electrically-conducting sheet is connected to n-side of the diode-laser bar and the other electrically-conducting sheet is connected to p-side of the diode-laser bar.

Abstract: An apparatus for generating and amplifying laser beams at approximately 1 micrometer wavelength is disclosed. The apparatus includes an ytterbium-doped gain-crystal pumped by an ytterbium fiber-laser. The fiber-laser enables a pump wavelength to be selected that minimizes heating of the gain-crystal. The apparatus can be configured for generating and amplifying ultra-fast pulses, utilizing the gain-bandwidth of ytterbium-doped gain-crystals.

Abstract: Laser-machining apparatus includes a carbon monoxide (CO) laser emitting a beam of laser-radiation having forty-four different wavelength components and optical elements for delivering the radiation to workpiece. An acousto-optic modulator is provided for modulating the beam on the workpiece. A birefringent plate is provided in the beam transported to the workpiece for randomly polarizing radiation incident on the workpiece. A minimum distance of the workpiece from the laser, and the number of different-wavelength components in the laser beam provides that no optical isolator is required for preventing feedback of radiation into the laser.

Abstract: Methods of and devices for forming edge chamfers and through holes and slots on a material that is machined using a laser, such as an ultrafast laser. The shaped material has predetermined and highly controllable geometric shape and/or surface morphology. Further, a method of and a device for preventing re-deposition of the particles on a material that is machined using a laser, such as an ultrafast laser. A fluid is used to wash off the particles generated during the laser machining process. The fluid can be in a non-neutral condition, with one or more chemical salts added, or a condition allowing the coagulation of the particles in the fluid, such that the particles can be precipitated to avoid the reattachment to the machined substrate.

Abstract: A cooler for diode-laser bars comprises a machined base including a water-input plenum and a water-output plenum, and a top plate on which the diode-laser bars can be mounted. A stack of three etched plates is provided between the base and first plate. The stack of etched plates is configured to provide a five longitudinally spaced-apart rows of eight laterally spaced-apart cooling-channels connected to the water-input and water-output plenums. Water flows in the cooling-channels and in thermal contact with the first plate.

Abstract: Apparatus for generating a line-beam includes a diode-laser bar, a linear micro-lens array, and a plurality of lenses spaced apart and arranged along an optical axis. The linear micro-lens array and the lenses shape laser-radiation emitted by the diode-laser bar to form a uniform line-beam in an illumination plane. The lenses project a far-field image of the diode-laser bar onto an image plane proximate to the illumination plane. The diode-laser bar is rotated from parallel alignment with the linear micro-lens array for providing uniform line-beam illumination over a range of locations along the optical axis.

Abstract: In a line projector a diode-laser beam having an elliptical cross-section is projected onto a Powell lens which spreads the beam to form a line of light. Distribution of power along the line of light is adjusted by rotating the diode-laser beam with respect to the Powell lens.

Abstract: Plane-polarized laser-radiation from a laser-source is converted to circularly polarized radiation by a quarter-wave plate. The circularly polarized radiation is input into a hollow-core fiber for transport to a point of use. The transported radiation is converted back to plane-polarized radiation by another quarter-wave plate between the fiber and the point of use.

Abstract: An architecture for current driver circuitry for diode laser systems is contemplated whereby the circuitry is both modular and minimally complex with respect to the number of components and connections.

Abstract: A source of femtosecond pulses at center wavelengths of about 940 nm and about 1140 nanometers (nm) includes a mode-locked fiber MOPA delivering pulses having a center wavelength of about 1040 nm. The 1040-nanometer pulses are spectrally spread into a continuum spectrum extending in range between about 900 nm and about 1200 nm and having well defined side-lobes around the 940-nm and 1140-wavelengths. Radiation is spatially selected from these side-lobes and delivered as the 940-nm and 1140-nm pulses.

Abstract: A carbon dioxide waveguide-laser includes an elongated resonator unit and an elongated power-supply unit. The resonator and power-supply units are spaced by a cooling unit including a plurality of longitudinally extending, spaced-apart fins, with fans arranged to drive air through the spaces between the fins.