Unstable resonator with variable output coupling
Granted: July 13, 2010
Patent Number:
7756186
Through the use of a relatively inexpensive third mirror on a novel folded hybrid unstable resonator configuration, the optimum output coupling for a given laser design can be explored quickly and easily with a minimum of intracavity mirror alignment. No changes in either the radii of curvature of the three cavity optics or their spacing are required for this exploration. In addition to providing techniques for purposefully and systematically introducing mirror edge effects or avoiding…
Electrodes for generating a stable discharge in gas laser system
Granted: July 13, 2010
Patent Number:
7756184
Arcing is minimized in a discharge chamber of a gas laser system by utilizing an electrode which comprises a surface portion capable of functioning as one of an anode and a cathode in order to energize a gas mixture in a discharge chamber of the gas discharge laser system, a shoulder portion being positioned on either side of the surface portion and being exposed to the gas mixture, and a coating layer made of electrically insulating material, wherein the coating layer is attached to the…
Quasi-CW UV laser with low peak pulse-power
Granted: June 15, 2010
Patent Number:
7738515
Laser apparatus is disclosed in which fundamental-wavelength optical pulses delivered from a mode-locked laser resonator at a pulse-repetition frequency (PRF) are converted to harmonic-wavelength pulses in an optical delay loop. One example is disclosed in which the harmonic-wavelength pulses are delivered directly from the delay loop. Another example is disclosed in which the harmonic-wavelength pulses are divided by the delay loop into a number of temporally spaced-apart replicas…
Laser beam micro-smoothing
Granted: May 25, 2010
Patent Number:
7723169
The present invention provides laser beam micro-smoothing for laser annealing systems. Laser beam micro-smoothing comprises shifting a laser beam in the direction perpendicular to the scanning direction (y) of a laser annealing system, while holding the laser beam fixed in the direction of scanning (x). The shifting may be accomplished, for example, with a pair of micro-smoothing mirrors. The shifting smoothes out small-scale inhomogeneities in the profile of the laser beam and prevents…
Vacuum cell for optical components
Granted: May 25, 2010
Patent Number:
7724453
A moisture sensitive optically nonlinear crystal is enclosed in a hermetically sealed elongated vacuum cell. The vacuum cell has an input window at one end and an output window at an opposite end providing optical access to the crystal by a laser beam. The windows are attached to the cell by cold-formed, indium-metal ram-seals. In an example of the cell in which the crystal is arranged to generate UV radiation from the laser beam, the output window is located at a sufficient distance…
Multiple pulsed-laser system for silicon crystallization
Granted: May 25, 2010
Patent Number:
7724785
Multiple laser resonators share a common acousto-optic Q-switch. The Q-switch is driven by a radio-frequency (RF) transducer that causes an acoustic wave to propagate in the Q-switch. Turning off the RF transducer discontinues propagation of the acoustic wave and causes each of the laser resonators to deliver an optical pulse. The finite velocity of the acoustic wave causes the pulses to be delivered temporally spaced apart.
Attenuator for high-power unpolarized laser beams
Granted: April 27, 2010
Patent Number:
7706069
Apparatus for attenuating an unpolarized laser beam includes a polarizing beamsplitter for separating the laser beam into two plane-polarized beams following separate paths. The two plane-polarized beams are polarization rotated by a single polarization rotator. Each of the polarization-rotated beams is separated by a polarizing beam-combiner into two plane-polarized portions. One of the portions of one polarization-rotated beam is combined by the beam-combiner with one of the portions…
High power and high brightness diode-laser array for material processing applications
Granted: April 13, 2010
Patent Number:
7697207
Arrangements for combination and fast-axis alignment of fast-axes of diode-laser beams are disclosed. Alignment arrangements include providing each diode-laser with a corresponding alignable fast-axis collimating lens, providing individually alignable mirrors for steering an re-orienting beams from each diode-laser, and providing single diode-laser slab-modules in which the diode-laser beams can be pre-aligned to a common propagation-axis direction, and in which edges and surfaces of the…
Repetitively pulsed laser and amplifier with dual resonator for pulse-energy management
Granted: April 6, 2010
Patent Number:
7692854
A regenerative amplifier includes a gain-medium that is optically pumped by CW radiation. The amplifier has primary resonator for amplifying pulses. The primary resonator has an optical switch for opening and closing the primary resonator. The amplifier has a secondary resonator that includes the gain-medium and a selectively variable attenuator, but not the optical switch. The optical switch and the variable attenuator are cooperatively controlled in response to repeated trigger-signals…
Pre-ionizer for pulsed gas-discharge laser
Granted: April 6, 2010
Patent Number:
7693207
In a CO2 laser a pre-ionizer is assembled in a flange configured to be attached to a laser-gas enclosure of the laser over an aperture in a wall of the enclosure. An aperture in the base of the flange is aligned over the aperture in the enclosure wall. The aperture in the pre-ionizer flange is covered by a ceramic membrane. A disc electrode is in contact with the ceramic membrane on a side of the membrane outside of the laser-gas enclosure. An RF potential applied to the disc electrode…
Lensed dual diode-laser bar package
Granted: March 30, 2010
Patent Number:
7686224
A diode-laser bar package includes two diode-laser bars mounted on a heat sink with slow-axes of the diode-laser bars aligned. Three spaced apart mounting bosses extend from the front of the heat sink. The package includes two cylindrical lens assemblies. Each lens assembly has an elongated cylindrical lens bonded to a rectangular mounting block. The cylindrical lenses are aligned with the diode-laser bars. Lateral faces of the mounting block are epoxy-bonded to lateral faces of the…
Non-fourier pulse-shapers including a combined pulse-shaper and pulse-compressor
Granted: March 30, 2010
Patent Number:
7688493
A pulse-shaper for temporally shaping an optical pulse includes a prism or a grism arranged to disperse the optical pulse into a diverging fan of spectral-component rays. The fan of spectral-component rays is collimated by a lens or another grism. The collimated spectral-component rays are selectively modulated by a spatial-light-modulator (SLM). The modulated rays from the SLM are either recombined to form the temporally shaped pulse by another lens and another prism, another two…
Sub-millimeter wave frequency heterodyne detector system
Granted: March 30, 2010
Patent Number:
7687773
The present invention relates to sub-millimeter wave frequency heterodyne imaging systems. More specifically, the present invention relates to a sub-millimeter wave frequency heterodyne detector system for imaging the magnitude and phase of transmitted power through or reflected power off of mechanically scanned samples at sub-millimeter wave frequencies.
Apparatus for providing multiple time-division multiplexed independently controllable pulsed beams from a single, pulsed laser output-beam
Granted: March 9, 2010
Patent Number:
7675673
An output beam from a laser is directed into an acousto-optic cell. The laser beam includes repeated sequences of two or more pulses. The acousto-optic cell is sequentially driven by RF voltages at two or more frequencies. A portion of the laser output beam is diffracted by the acousto-optic cell at two or more different angles to the laser output beam. This provides two or more secondary beams. One of the secondary beams includes only the first pulses of the sequences; the other…
Thermal distortion compensation for laser mirrors
Granted: February 16, 2010
Patent Number:
7664159
A laser mirror assembly is disclosed with improved pointing stability. An elongated mirror includes a concave reflecting portion. A pair of elongated planar portions extend parallel to the concave reflecting portion on either side thereof. The planar portions are stepped down from the reflecting portion. The mirror is formed from copper. A pair of stainless steel strips are connected to planar portions. The bimetallic effect between the copper mirror and the stainless steel strips…
Focus determination for laser-mask imaging systems
Granted: February 9, 2010
Patent Number:
7659989
A system and method for calibrating the focal position of the imaging plane of a sequential lateral solidification (SLS) system. A test pattern is formed on a test substrate while varying the z-position of the focal position. Information concerning the z-position of the focal position is stored by a data processing system for various positions in the test pattern. An inspection light beam is directed onto the test pattern at a predetermined angle. The reflection of the inspection light…
First-pulse suppression in a regenerative amplifier
Granted: January 19, 2010
Patent Number:
7649924
A regenerative amplifier includes a gain-medium that is optically pumped by CW radiation. The amplifier has primary resonator for amplifying pulses. The primary resonator has an optical switch for opening and closing the primary resonator. The amplifier has a secondary resonator that includes the gain-medium but not the optical switch. When the primary resonator is closed by the optical switch, and pulses are not being amplified, CW radiation is generated in the secondary resonator and…
High-power external-cavity optically-pumped semiconductor lasers
Granted: January 5, 2010
Patent Number:
7643530
External-cavity optically-pumped semiconductor lasers (OPS-lasers) including an OPS-structure having a mirror-structure surmounted by a surface-emitting, semiconductor multilayer (periodic) gain-structure are disclosed. The gain-structure is pumped by light from diode-lasers. The OPS-lasers can provide fundamental laser output-power of about two Watts (2.0 W) or greater. Intracavity frequency-converted arrangements of the OPS-lasers can provide harmonic laser output-power of about…
Laminated wafer sensor system for UV dose measurement
Granted: December 29, 2009
Patent Number:
7638798
A laminated wafer sensor structure includes a housing layer having pocket openings formed therein, a circuit layer having a sensor element and electronic components mounted for registration with the pocket openings in the housing layer, and a rigid back layer. The laminated structure is suitable for handling by conventional robotic wafer handling systems. The wafer sensor structure is adapted for electrical connection to a base station that is also adapted for connection to a host…
Laser illuminated projection displays
Granted: December 15, 2009
Patent Number:
7633562
A projection video display includes a light source including an OPS-laser delivering laser radiation in multiple transverse modes (a multiple-transverse-mode OPS-laser). The display includes a spatial light modulator for spatially modulating the radiation from the multiple-transverse-mode OPS-laser in accordance with a portion of an image to be displayed. Projection optics project the spatially modulated light on a screen on which the image is to be displayed. In one example the…
