Abstract: A method of adjusting depth of focus in a laser milling system includes generating a laser beam having a focal plane, positioning a workpiece in the focal plane with a surface of the workpiece exposed to the laser beam at a point intersecting the focal plane, and adjusting a position of the workpiece or the focal plane to maintain a constant ablation rate on the exposed surface of the workpiece throughout the drilling process.

Abstract: A method of laser milling an aperture in a workpiece for use with manufacturing ink-jet nozzles includes initially illuminating a surface of the workpiece with a laser beam at a point within an outer perimeter of a desired aperture and a distance away from the outer perimeter sufficient to substantially avoid initial ablation of the outer perimeter. The laser beam is driven substantially in the direction of the outer perimeter at a variable rate controlled to avoid deformation of the outer perimeter. Material of the workpiece is ablated in a pattern designed to substantially remove material within the outer perimeter, thereby forming the aperture.

Abstract: The present invention is a system for laser micromachining where a scan mirror and milling algorithm are used to produce high precision, controlled hole shapes in a workpiece. A picosecond laser that produces short pulses is used to reduce thermal effects to improve the quality and repeatability of the milled holes, and a Diffractive Optical Element (DOE) is used to split a single beam into a plurality of beams to allow parallel drilling of the workpiece. A method for operating a laser drilling system where high precision, controlled hole shapes in a workpiece are drilled includes using a scan mirror and milling algorithm, and using a picosecond laser in conjunction with a DOE, thus ensuring that spectral bandwidth issues and thermal issues are addressed to improve the quality and repeatability of the holes.

Abstract: A microfilter design system for use with a laser drilling system producing multiple sub-beams for parallel drilling operations includes an optical intensity detector illuminated by the multiple sub-beams of the laser drilling system. An analysis module operates the optical intensity detector to produce intensity measurement data for each of the multiple sub-beams. A memory operable with a data processing system stores the intensity measurement data for analysis.

Abstract: A method is provided for aligning a workpiece in a laser drilling system. The method includes: providing a workpiece having at least two substantially planar and parallel surfaces, including a first planar surface in which ablations are formed therein by the laser drilling system; propagating an alignment beam of light towards a second planar surface of the workpiece, the alignment beam being incident on and reflected by the second planar surface, thereby forming a reflected beam of light; measuring a reflection angle of the reflected beam; and determining alignment information for the workpiece based on the measured reflection angle of the reflected beam. The method may further include adjusting alignment of the workpiece based on the alignment information.

Abstract: A method of laser milling an aperture in a workpiece for use with manufacturing ink-jet nozzles includes initially illuminating a surface of the workpiece with a laser beam at a point within an outer perimeter of a desired aperture and a distance away from the outer perimeter sufficient to substantially avoid initial ablation of the outer perimeter. The laser beam is driven substantially in the direction of the outer perimeter at a variable rate controlled to avoid deformation of the outer perimeter. Material of the workpiece is ablated in a pattern designed to substantially remove material within the outer perimeter, thereby forming the aperture.

Abstract: A method is provided for determining a minimum pulse width for a pulsed laser beam in a short pulse laser system, such that the minimum pulse width accounts for dispersion associated with the pulse laser beam passing through a diffractive optical element. The method includes: determining size data for an ablation to be formed in a surface of a workpiece; determining an operating wavelength for a pulsed laser beam; determining spot size data for the beam incident on the workpiece; determining tolerance data for the spot size of the incident beam; and determining a minimum pulse width for the pulsed laser beam based on the size data for the ablation, the operating wavelength for the laser beam, the spot size data for the laser beam and the tolerance data for the spot size.

Abstract: A method of adjusting depth of focus in a laser milling system includes generating a laser beam having a focal plane, positioning a workpiece in the focal plane, wherein a surface of the workpiece is exposed to the laser beam at a point intersecting the focal plane, and adjusting a position of at least one of the workpiece and the focal plane, thereby maintaining a constant ablation rate on the exposed surface of the workpiece throughout the drilling process.

Abstract: A computer interface system for automated control of a laser drilling system has workpiece geometry template data defining a shape formed in a laser-milled workpiece. A user interface is receptive of a user selection characterizing a desired laser drilling operation. An expert system is adapted to receive the template data and the user selection, and is operable to adapt the template data to the user selection.

Abstract: A method is provided for aligning a workpiece in a laser drilling system. The method includes: providing a workpiece having at least two substantially planar and parallel surfaces, including a first planar surface in which ablations are formed therein by the laser drilling system; propagating an alignment beam of light towards a second planar surface of the workpiece, the alignment beam being incident on and reflected by the second planar surface, thereby forming a reflected beam of light; measuring a reflection angle of the reflected beam; and determining alignment information for the workpiece based on the measured reflection angle of the reflected beam. The method may further include adjusting alignment of the workpiece based on the alignment information.

Abstract: A method of determining compatibility of user input parameters for use with a laser drilling system includes providing compatibility data characteristic of a plurality of laser drilling operations, receiving input parameters characteristic of a desired laser drilling operation, and comparing the input parameters to the compatibility data, thereby determining whether the input parameters are incompatible.

Abstract: A microfilter design system for use with a laser drilling system producing multiple sub-beams for parallel drilling operations includes an optical intensity detector illuminated by the multiple sub-beams of the laser drilling system. An analysis module operates the optical intensity detector to produce intensity measurement data for each of the multiple sub-beams. A memory operable with a data processing system stores the intensity measurement data for analysis.

Abstract: A system and method for aligning a microfilter in an optical circuit and thereby providing sub-beam impingement intensity control from a set of highly proximate sub-beams generated from a parallel process laser system removing a portion from a workpiece (exit holes in inkjet nozzle plates). The energy of laser-generated sub-beams to the target (cutting) point is attenuated to a level sufficient for maintaining operation of a charge-coupled-device camera below saturation when the sub-beams are incident on the camera, the CCD camera monitors the sub-beams and directs output to either a monitor or control computer. The microfilter is then adjusted to provide an optimal sub-beam pattern.

Abstract: A laser processing apparatus includes a laser generation apparatus for outputting an ultra-short pulse laser beam, a laser control apparatus for controlling the laser generation apparatus, an optical system, an optical system control apparatus for measuring the optical system, and a measurement apparatus for measuring the ultra-short pulse laser beam. The intensity of the largest noise component pulse in the ultra-short pulse laser beam is controlled to be 2.5% or less of the intensity of the primary pulse in the ultra-short pulse laser beam.

Abstract: A photonic crystal comprising a waveguide made of material. The waveguide has a periodic set of holes. The material proximate to at least one of the holes in the periodic set of holes exhibits an index of refraction that has been modified by the application of laser energy relative to the material proximate to other holes in the periodic set of holes. The photonic crystal is tuned to temporarily transmit a specific wavelength of light to create an on-off switch for the specific wavelength. Multiple photonic crystals are used to form a multiplexer and a demultiplexer.

Abstract: An improved workpiece holder is provided for use in a laser drilling system. The workpiece holder includes: a body having at least one planar support surface adapted to support a workpiece; a plurality of recesses formed in the planar support surface; at least one groove formed in the planar support surface; and a vacuum passage extending through the body of the holder. In addition, the plurality of recesses may be configured to align with the drilling pattern of the laser drilling system.

Abstract: A tuned optical resonator having a substrate and an input waveguide and an optical resonator waveguide formed on the substrate. The optical resonator waveguide has a resonant frequency, exhibits a first index of refraction, temporarily exhibits a second index of refraction responsive to application of laser energy, and temporarily resonates at the resonant frequency while the laser energy is being applied.

Abstract: A photonic crystal comprising a waveguide made of material. The waveguide has a periodic set of holes. The material proximate to at least one of the holes in the periodic set of holes exhibits an index of refraction that has been modified by the application of laser energy relative to the material proximate to other holes in the periodic set of holes.

Abstract: A diode-pumped, solid-state laser (52) of a laser system (50) provides ultraviolet Gaussian output (54) that is converted by a diffractive optical element (90) into shaped output (94) having a uniform irradiance profile. A high percentage of the shaped output (94) is focused through an aperture of a mask (98) to provide imaged to provide imaged shaped output (118). The laser system (50) facilitates a method for increasing the throughput of a via drilling process over that available with an analogous clipped Gaussian laser system. This method is particularly advantageous for drilling blind vias (20b) that have better edge, bottom, and taper qualities than those produced by a clipped Gaussian laser system. An alternative laser system (150) employs a pair of beam diverting galvanometer mirrors (152, 154) that directs the Gaussian output around a shaped imaging system (70) that includes a diffractive optical element (90) and a mask (98).

Abstract: The invention is an apparatus and a method for drilling holes in a work piece with a laser. A laser beam is received by the optical system and directed along an optical path. The system directs the laser beam through a moveable mask aperture creating a sub-beam, that is reduced in size by a lens system as it is imaged onto a work piece. Multiple features are formed in the work piece by moving the mask.