Abstract: Systems and methods are described for forming continuous laser filaments in transparent materials. A burst of ultrafast laser pulses is focused such that a beam waist is formed external to the material being processed without forming an external plasma channel, while a sufficient energy density is formed within an extended region within the material to support the formation of a continuous filament, without causing optical breakdown within the material. Filaments formed according to this method may exhibit lengths exceeding up to 10 mm. In some embodiments, an aberrated optical focusing element is employed to produce an external beam waist while producing distributed focusing of the incident beam within the material. Various systems are described that facilitate the formation of filament arrays within transparent substrates for cleaving/singulation and/or marking. Optical monitoring of the filaments may be employed to provide feedback to facilitate active control of the process.

Abstract: A scanning laser apparatus for alternately processing two workstations includes a 2D laser beam scanner and a roof reflector. The roof reflector has two reflective surfaces located on the left and right sides, respectively, of the roof “ridge”. The laser beam scanner directs the laser beam to either one of the left and right reflective surfaces of the roof reflector. When the laser beam scanner directs the laser beam to the left (or right) reflective surface, the left (or right) reflective surface reflects the laser beam toward a workstation on the left (or right) side of the roof ridge. The roof reflector divides the field of view of the laser beam scanner between the workstations. While a workpiece is being removed from or mounted in the left workstation, another workpiece may undergo scanning laser processing in the right workstation, and vice versa, thereby facilitating high throughput.

Abstract: An apparatus, and associated method, laser cuts self-wrapping, woven or braided split sleeves from a continuous feed of sleeve material by sweeping a laser beam across the continuously fed material. Instead of sweeping the laser beam straight across the material in a direction perpendicular to the longitudinal axis of the material, the sweep path is angled to follow the feed rate of the material while the laser beam cuts through the material from one side to the other. Thus, a straight cut may be completed without stopping the feed. The apparatus includes a mandrel tor expanding the material before intersection with the laser beam to open a gap at the longitudinal split. The mandrel has a wedge-shaped tip with an end-surface profile that is at an oblique angle to the direction of motion of the material. The oblique angle at least approximately matches the sweep angle of the laser beam.

Abstract: An apparatus for radial laser processing of a workpiece, located on a center axis, includes a laser beam scanner directing a laser beam along but offset from the center axis, and a bi-conical reflector system including first and second conical mirror surfaces surrounding the center axis. The first conical mirror surface faces away from the center axis to reflect the laser beam radially outwards therefrom, toward the second conical mirror surface. The second conical mirror surface faces the center axis to reflect the laser beam radially inwards toward the workpiece. The laser beam scanner azimuthally scans a location of incidence of the laser beam on the first conical mirror surface to scan an azimuthal angle of propagation of the laser beam from the second conical mirror surface toward the workpiece. The apparatus enables irradiation of the entire circumference of the workpiece without physically rotating the workpiece.

Abstract: A method for machining and releasing closed forms from a transparent, brittle substrate includes using a burst of ultrafast laser pulses to drill patterns of orifices in the substrate. Orifices are formed by photoacoustic compression and they extend completely or partially in the transparent substrate. A scribed line of spaced apart orifices in the transparent substrate comprise a closed form pattern in the substrate. A heat source is applied in a region about said scribed line of spaced apart orifices until the closed form pattern releases from the transparent substrate.

Abstract: A method is provided for the internal processing of a transparent substrate in preparation for a cleaving step. The substrate is irradiated with a focused laser beam that is comprised of pulses having an energy and pulse duration selected to produce a filament within the substrate. The substrate is translated relative to the laser beam to irradiate the substrate and produce an additional filament at one or more additional locations. The resulting filaments form an array defining an internally scribed path for cleaving said substrate. Laser beam parameters may be varied to adjust the filament length and position, and to optionally introduce V-channels or grooves, rendering bevels to the laser-cleaved edges. Preferably, the laser pulses are delivered in a burst train for lowering the energy threshold for filament formation and increasing the filament length.

Abstract: Very fine closed form structures can be scribed via filamentation in the transparent substrate very quickly, the modified zone can be etched via dry or wet chemical etching to release the closed form. A metal layer engages the transparent substrate and is covered with photoresist. A portion of the photoresist and a portion of the metal are removed simultaneously with the creation of a filament through the transparent substrate. The photoresist protects the portion of the metal layer that is not removed. The desired closed form can be released by weakening the cut region using dry or wet chemical etching to remove the desired part.

Abstract: An apparatus, system and method for the processing of orifices in materials by laser filamentation that utilizes an optical configuration that focuses the incident laser light beam in a distributed manner along the longitudinal beam axis. This distributed focusing method enables the formation of filaments over distances, and the laser and focusing parameters are adjusted to determine the filament propagation and termination points so as to develop a single/double end stopped orifice, or a through orifice. Selected transparent substrates from a stacked or nested configuration may have orifices formed therein/therethrough without affecting the adjacent substrate. These distributed focusing methods support the formation filaments with lengths well beyond ten millimeters in borosilicate glass and similar brittle materials and semiconductors.

Abstract: A process of forward deposition of a material onto a target substrate is accomplished by passing a burst of ultrafast laser pulses of a laser beam through a carrier substrate that is transparent to a laser beam. The carrier substrate is coated with a material to be transferred on the bottom side thereof. Electrons on the back side of said transparent carrier coated with the material are excited by the first few sub-pulses of the laser beam which lifts the material from the carrier substrate and subsequent sub-pulse of the laser beam send the material into space at hypersonic speed by a shock wave that drives the material with forward momentum across a narrow gap between the carrier substrate and the target substrate, and onto the target substrate.

Abstract: A method for laser processing of Silicon includes placing a Kerr material into engagement with the Silicon forming an interface therebetween. A laser beam is applied having at least one subpulse in a burst envelope operating at a first wavelength. The laser beam passes through a distributive lens focusing assembly and to the Kerr material. The first wavelength is modified to a plurality of second wavelengths, some of which are effective for processing Silicon. Photoacoustic compression processing is produced by the laser pulse energy by a portion of second wavelengths delivered through the interface and to the Silicon which initiates Kerr Effect self focusing which is propagated in the Silicon by additional energy input to the Silicon thus producing a filament within the Silicon.

Abstract: A non-ablative method and apparatus for making an economical glass hard disk (platter) for a computer hard disk drive (HDD) using a material machining technique involving filamentation by burst ultrafast laser pulses. Two related methods disclosed, differing only in whether the glass substrate the HDD platter is to be cut from has been coated with all the necessary material layers to function as a magnetic media in a computer's hard drive. Platter blanks are precisely cut using filamentation by burst ultrafast laser pulses such that the blank's edges need not be ground, the platter's geometric circularity need not be corrected and there is no need for further surface polishing. Thus the platters can be cut from raw glass or coated glass. As a result, this method reduces the product contamination, speeds up production, and realizes great reductions in the quantity of waste materials and lower production costs.

Abstract: Systems and methods are described for forming continuous curved laser filaments in transparent materials. The filaments are preferably curved and C-shaped. Filaments may employ other curved profiles (shapes). A burst of ultrafast laser pulses is focused such that a beam waist is formed external to the material being processed without forming an external plasma channel, while a sufficient energy density is formed within an extended region within the material to support the formation of a continuous filament, without causing optical breakdown within the material. Filaments formed according to this method may exhibit lengths in the range of 100 ?m-10 mm. An aberrated optical focusing element is employed to produce an external beam waist while producing distributed focusing of the incident beam within the material. Optical monitoring of the filaments may be employed to provide feedback to facilitate active control of the process.

Abstract: A method of producing a spiral cut transparent tube using laser machining includes using an ultrafast laser beam comprising a burst of laser pulses and focusing the laser beam on the transparent tube to enable relative movement between the laser beam and the transparent tube by moving the laser beam, the glass tube or both the laser beam and the glass tube. A beam waist is formed external to the surface of the transparent tube wherein the laser pulses and sufficient energy density is maintained within the transparent tube to form a continuous laser filament therethrough without causing optical breakdown. The method and delivery system makes a spiral cut in the transparent tube.

Abstract: A method of drilling multiple orifices in and texturing a substrate is disclosed and includes the following steps. Ultrafast laser pulses are passed through a beam splitting diffractive optical element and then multiple beams are passed through a distributive-focus lens focusing assembly. The relative distance and/or angle of said distributive-focus lens focusing assembly in relation to the laser source is adjusted focusing the pulses in a distributed focus configuration creating a principal focal waist and at least one secondary focal waist. The fluence level of the at least one secondary focal waists is adjusted such that it is or they are of sufficient intensity and number to ensure propagation of multiple filaments in the substrate. Photoacoustic compressive machining is performed and forms multiple volume(s) within the substrate.