Abstract: A multicore optical fiber with an integral diffractive element. The multicore optical fiber includes: a first optical fiber core formed of a non-photosensitive material having an initial index of refraction; and a second optical fiber core including a second longitudinal core axis substantially parallel to the first longitudinal axis. The first optical fiber core includes: a first longitudinal core axis; and a number of index-altered portions having an altered index of refraction which is different from the initial index of refraction. The index-altered portions are arranged within the non-photosensitive material of the first optical fiber core to form a diffractive structure of the integral diffractive element.

Abstract: An ultrafast laser machining system and method to form diffractive structures in optical fibers. The fiber is mounted with its longitudinal axis perpendicular to the beam path of the laser pulses. A region of the fiber is illuminated and then imaged with two cameras. These cameras are aligned substantially orthogonally. A position of the beam spot is determined. The beam spot is aligned to a starting position within the region. This position is within a portion of the fiber to be machined for which the beam path passes through the greatest length of material. The beam spot is scanned along a path designed to pass the beam spot through all of the portion to be machined such that the beam path does not pass through previously machined material. The laser pulses, which have a duration of less than about 1 ns, are generated as the beam spot is scanned.

Abstract: A vibration machining apparatus and method of use. The vibration machining apparatus includes a cutting tool and a motion stage coupled to one of the cutting tool or the workpiece to move the cutting tool relative to the workpiece. A tangent to a machine path and a normal to the surface of the workpiece define a vibration plane. The vibration machining apparatus further includes a first vibrating unit coupled to one of the cutting tool or the workpiece to vibrate it along a first vibrational direction, substantially in the vibration plane, and a second vibrating unit coupled with one of the cutting tool or the workpiece to vibrate the one of the cutting tool or the workpiece coupled to the second vibrating unit along a second vibrational direction, different from the first direction and substantially in the vibration plane.

Abstract: A slab laser amplifier with parasitic oscillation suppression has a plurality of angled pump faces related to one another in order to decrease likelihood of parasitic oscillations, with internal beam incidence angles at total internal reflection that alleviate need for reflective coatings. No polished surfaces of gain material comprising the amplifier are parallel to one another. A beam path within the gain material is such that all incident angles of the beam path upon the two main faces and the common end face are greater than a critical angle required for total internal reflection, thereby alleviating need for reflective coatings. Based on an index of refraction of the gain material, and based on a diameter of the laser beam, dimensions of the gain material are selected to maximize beam overlap in a pumped volume of the gain material.

Abstract: The present invention is a method of selecting composite sheet materials for use in ultra-fast laser patterning of layers of organic thin film material such as OLEDs. The material is selected to accomplish patterning of upper layers without damaging underlying layers by using an ultra-fast laser programmed with the appropriate laser processing parameters. These parameters are derived by examining each layer's absorption spectra, thermal, and chemical characteristics. The method of the present invention includes measuring each layer's absorption spectrum, examining each layer's thermal and chemical characteristics, determining if the layer is ablatable, determining the laser setup, patterning the layer through laser ablation processing, and determining if more layers need to be ablated. Further, the method includes a sub-method of selecting an alternate material if a layer's material characteristics are not favorable for ablation without damaging underlying layers.

Abstract: An ultrafast laser machining system and method to form diffractive structures in optical fibers. The fiber is mounted with its longitudinal axis perpendicular to the beam path of the laser pulses. A region of the fiber is illuminated and then imaged with two cameras. These cameras are aligned substantially orthogonally. A position of the beam spot is determined. The beam spot is aligned to a starting position within the region. This position is within a portion of the fiber to be machined for which the beam path passes through the greatest length of material. The beam spot is scanned along a path designed to pass the beam spot through all of the portion to be machined such that the beam path does not pass through previously machined material. The laser pulses, which have a duration of less than about 1 ns, are generated as the beam spot is scanned.

Abstract: An apparatus and method for making a grayscale photo mask and a three-dimensional grayscale diffractive optical element operate as follows. A grayscale photo mask is obtained by exposing a laser direct write (LDW) glass material to laser beam radiation from a first laser beam of modulated power moved over a grid of discrete locations on the LDW material, the modulated power being in accordance with grayscale pattern data, and, while the first laser beam is moved over the discrete locations of the grid, exposing the grid to a second laser beam, the power of the second laser beam being less than the bleach threshold of the glass material, to provide each of the discrete locations with a gray scale level to provide a predetermined gray scale pattern of varying optical transmissivity on the LDW material to produce a grayscale mask.

Abstract: A laser rod and methods of manufacturing a plurality of laser rods such that each laser rod has two polished end surfaces and an optical axis that extends between the two polished end surfaces. The laser rod includes a gain material component that has a substantially prismatic shape. The gain material component includes: a first end surface that is substantially optically smooth; a second end surface that is substantially optically smooth; at least three flat side surfaces; and an optical axis, which is substantially parallel to the flat side surfaces. The optical axis intersects the first end surface at a first incidence angle and it intersects the second end surface at a second incidence angle.

Abstract: An optical fiber with an integral photonic crystal structure. The optical fiber core is formed of a non-photosensitive material having an initial index of refraction. The optical fiber core includes a substantially cylindrical surface, a longitudinal core axis, a core radius, and a number of index-altered portions having an altered index of refraction different from the initial cladding index of refraction. The index-altered portions are arranged within the non-photosensitive material of the optical fiber core to form a photonic crystal structure. The photonic crystal structure may be a one dimensional, a two dimensional, or a three dimensional photonic crystal structure.

Abstract: A structured diamond tool having a predefined grayscale grating profile shape allows a corresponding grayscale grating profile to be machined into a work piece with a single pass with high accuracy. Manufacture of grayscale gratings using this technique saves time compared to the situation where the profile is machined by a single-point diamond tool with multiple passes. Also, more time-saving is realized if more than one period is machined in the diamond tool. Such a tool can be manufactured using a high precision focused ion beam (FIB), which is a true nanomachining tool that can machine features on the order of tens of nanometers. The diamond tool made by FIB therefore has extremely fine resolution and features required by the grayscale grating.

Abstract: A multimode long period fiber Bragg grating (LPFBG) for a predetermined wavelength band. The LPFBG formed of a non-photosensitive material having an initial index of refraction. The multimode optical fiber core includes a substantially cylindrical surface, a longitudinal core axis, a core radius, and a number of index-altered portions having an altered index of refraction different from the initial cladding index of refraction. Each of the index-altered multimode optical fiber core has a first transmission surface and second transmission surface that is substantially parallel to the first transmission surface. Also, these index-altered portions are arranged within the non-photosensitive material of the multimode optical fiber core such that the first transmission surface of one portion of the plurality of index-altered portions is substantially parallel to the second transmission surface of a neighboring portion to form a long period Bragg grating structure.

Abstract: An ultrafast laser machining system and method to form diffractive structures in optical fibers. The fiber is mounted with its longitudinal axis perpendicular to the beam path of the laser pulses. A region of the fiber is illuminated and then imaged with two cameras. These cameras are aligned substantially orthogonally. A position of the beam spot is determined. The beam spot is aligned to a starting position within the region. This position is within a portion of the fiber to be machined for which the beam path passes through the greatest length of material. The beam spot is scanned along a path designed to pass the beam spot through all of the portion to be machined such that the beam path does not pass through previously machined material. The laser pulses, which have a duration of less than about 1 ns, are generated as the beam spot is scanned.

Abstract: A method is provided for manufacturing a high-precision mold whereby a feature matching a desired feature design is carved into a hard mold material (41) using, for example, a diamond grinding wheel and/or a diamond turning point. Inherent imprecision and errors (49) introduced by the use of the grinding wheel/turning point are measured to determine deviations from the desired feature design. An ultrafast shortpulse laser is then activated to desirably ablate the deviations, thereby correcting the errors and conforming the feature to the desired shape. Furthermore, a thin film (1602) may be formed over the feature either prior to or after the laser ablation process, where the error measurement and laser ablation processes detects and ablates errors on the surface of the thin film, respectively. Additionally, the laser ablation process may be applied directly to, for example, an optical lens (1400) formed from an imprecise mold to remove any errors and imperfections thereon.

Abstract: An optically-pumped, amplified laser source including a single optical pump. The laser source includes: an optical pump to generate pump light; a laser oscillator adapted to generate laser light when irradiated with the pump light; a laser amplifier coupled to the laser oscillator to receive laser light from the laser oscillator; and beam splitting optics optically coupled to the optical pump, laser oscillator, and laser amplifier. The pump light includes a pump power and a predetermined pump wavelength and the laser light has a laser wavelength. The laser amplifier is adapted to amplify light with the laser wavelength when irradiated with light having the pump wavelength. The beam splitting optics couple a first portion of the pump light having a first fraction of the pump power into the laser oscillator and a second portion of the pump light having a second fraction of the pump power into the laser amplifier.

Abstract: A precision machining system with a variable projected machining width of the cutting surface of the machining tool, including: a workpiece holder to hold a workpiece; a machining tool holder to hold the machining tool such that the Z axis is substantially parallel to the tool's centerline; a Z translation stage and an X translation stage each coupled to one of the workpiece holder or the machining tool holder; a workpiece spindle coupled to the workpiece holder to rotate the workpiece about the workpiece axis that is parallel to the Z axis; a machining path controller electrically coupled to the X translation stage and the workpiece spindle; and a tool spindle coupled to the machining tool holder. The tool spindle rotates the machining tool about the centerline of the machining tool, which varies the width of the cutting surface of the machining tool projected perpendicular to the machining path.

Abstract: A machining tool with a cutting surface adapted to provide a variable projected machining width during machining, including the cutting surface and a back surface. The cutting surface includes a first cutting edge and a second cutting edge that extend to a tip of the machining tool and a cross section normal to a centerline of the machining tool that is concave between the first cutting edge and the second cutting edge. The back surface forms a first acute angle with the cutting surface at the first cutting edge and a second acute angle with the cutting surface at the second cutting edge, such that the cross section of the back surface normal to the centerline of the machining tool is convex between the first cutting edge and the second cutting edge.

Abstract: A method of etching a feature in a surface of a substrate. The substrate is provided. A photoresist layer is formed on the surface of the substrate. A thickness profile of the formed photoresist layer is determined. A grayscale scanning pattern is determined based on the feature and the thickness profile of the photoresist layer. The determined grayscale scanning pattern is laser written on the photoresist layer to expose a portion of the photoresist layer. The exposed portion of the photoresist layer is removed to form a grayscale pattern in the photoresist layer. The photoresist layer and the surface of the substrate are etched to form the feature in the surface of the substrate.

Abstract: A diffractive optical element (DOE), including a substrate formed of a substantially transparent material having a substrate index of refraction. The substrate includes a first transmission face that is substantially planar and a second transmission face that is substantially parallel to the first transmission face. The second transmission face includes an array of non-rectangular pixels that form a complete tiling over the functional area of this face. For each of the non-rectangular pixels of the array, the phase shift of light transmitted through the substrate between the transmission faces is approximately equal to one of a set of predetermined phase shifts.

Abstract: A method of etching a feature in a surface of a substrate. The substrate is provided. A photoresist layer is formed on the surface of the substrate. A thickness profile of the formed photoresist layer is determined. A grayscale scanning pattern is determined based on the feature and the thickness profile of the photoresist layer. The determined grayscale scanning pattern is laser written on the photoresist layer to expose a portion of the photoresist layer. The exposed portion of the photoresist layer is removed to form a grayscale pattern in the photoresist layer. The photoresist layer and the surface of the substrate are etched to form the feature in the surface of the substrate.

Abstract: The present invention is an optical pick-up system for use in an optical disk device including more efficient beam diffraction for tracking purposes. The system may be used for one or more types of optical disks (e.g., DVDs, CDs, CD-ROMs). The invention includes a system for use in a DVD player; however, the present invention is applicable to any optical disk device. The system invention includes a gray-scale grating, which provides more efficient diffraction of tracking and processing portions of the laser(s) used in optical disk devices.