Multimode MOPA with thermal lens compensation
Granted: November 17, 2009
Patent Number:
7620092
A master oscillator power amplifier (MOPA) laser system includes a symmetrical master oscillator and an amplifier each having an optically pumped solid-state gain rod. An optical relay is located between the laser resonator and the amplifier gain rod. When the oscillator and amplifier gain media are equally optically pumped, the magnification and the distances from the optical relay to the resonator and the amplifier gain rod can be selected such that amplifier efficiency is maximized,…
Amorphous silicon crystallization using combined beams from optically pumped semiconductor lasers
Granted: November 10, 2009
Patent Number:
7615722
An amorphous silicon layer on a glass substrate is crystallized by concentrating CW radiation from a number of OPS-lasers into a line of light on the layer. The layer is moved with respect to the line of light to control the dwell time of the line on any location on the layer and to crystallize an extended area of the layer.
Trace evidence detection using multiple laser light sources
Granted: November 10, 2009
Patent Number:
7615761
A method for detecting trace evidence materials on a surface comprises irradiating the surface with radiation from two or more lasers emitting radiation at different wavelengths selected to stimulate luminescence in the trace materials. The evidence is detected by observing the surface through an optical filter arranged to transmit the luminescence, while blocking transmission of the laser radiation wavelengths reflected or scattered from the surface.
Transformer for impedance-matching power output of RF amplifier to gas-laser discharge
Granted: October 20, 2009
Patent Number:
7605673
An RF impedance-matching transformer for matching the output impedance of an RF amplifier to the discharge of a gas-discharge laser includes upper and lower dielectric plates arranged face-to-face and bonded together. A primary U-shaped strip winding is embedded in the bonded surface of one of the dielectric plates. A secondary strip-winding is formed on an exposed surface of the upper dielectric plates. A ground-plane electrode formed on an exposed surface of the lower dielectric plate.…
MOPA laser apparatus with two master oscillators for generating ultraviolet radiation
Granted: September 22, 2009
Patent Number:
7593437
Laser apparatus including two different, pulsed MOPAs, one having a fundamental wavelength of 1064 nm and the other having a fundamental wavelength of 1547 nm, provide trains of optical pulses. The 1064-nm pulses are frequency-quadrupled to a wavelength of 266 nm. The 1547-nm pulses are first mixed with the 266-nm pulses to provide pulses having a wavelength of 227 nm. The 227-nm pulses are then mixed with residual 1547-nm pulses from the first mixing to provide 198-nm output pulses of…
MOPA laser apparatus with two master oscillators for generating ultraviolet radiation
Granted: September 22, 2009
Patent Number:
7593440
Laser apparatus including two different, pulsed MOPAs, one having a fundamental wavelength of 1064 nm and the other having a fundamental wavelength of 1564 nm, provide trains of optical pulses. The 1064-nm pulses are frequency tripled to 355 nm and the 1564-nm pulses are frequency doubled to 782 nm. The 355-nm and 782-nm pulses are mixed to provide 244-nm pulses. The 244-nm pulses are mixed with residual 1064-nm pulses to provide 198-nm output pulses of the apparatus. The output pulses…
Apparatus and method for stabilizing the frequency of lasers
Granted: September 1, 2009
Patent Number:
7583711
Method and apparatus are disclosed that enable lasers to be stabilized in absolute frequency to high precision. The principle of operation is to: 1) lock the laser frequency to an etalon transmission resonance, 2) phase modulate the laser beam at a frequency corresponding to the free spectral range of the etalon and lock the phase modulated sidebands to the etalon resonances, and 3) lock the etalon free spectral range frequency to a stable reference frequency derived from, e.g., a stable…
High power low inductance RF hermetic sealed feed-through for slab CO2 lasers
Granted: July 7, 2009
Patent Number:
7558308
A low inductance, hermetically sealed, RF shielded feed-through is provided for exciting low impedance discharges associated with high power CO2 slab lasers. The feed-through mechanically obtains RF contact, preferably, at the center of the length of the electrodes that are inserted within the long laser housing, thereby making it easier to obtain a uniform electric field distribution along the length of the electrodes.
Low stress optics mount using thermally conductive liquid metal or gel
Granted: June 23, 2009
Patent Number:
7551656
An optical assembly with mounting provided to effectively transfer heat away from an optic, such as a slab or waveguide amplifier or laser disk, while limiting internal stresses. The assembly includes an optic with a planar surface. A heat sink is positioned in the assembly with an upper surface next to the planar surface of the optic. The upper surface of the heat sink comprises a recessed surface defining a reservoir for containing a compliant heat transfer material. The assembly may…
Pre-ionizer for pulsed gas-discharge laser
Granted: June 9, 2009
Patent Number:
7545842
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…
Incoherent combination of laser beams
Granted: June 9, 2009
Patent Number:
7545838
A method of combining beams from a plurality of laser resonators includes frequency modulating the output of each of the lasers with one or more of the lasers frequency modulated out-of-phase with the others. The frequency modulated beams are directed along parallel spaced-apart paths and overlap in a plane along the paths to form a combined beam having a flat-topped intensity distribution.
RF shielded, series inductor, high RF power impedance matching interconnector for COslab laser
Granted: June 2, 2009
Patent Number:
7540779
A RF shielded, series inductor, high power impedance matching network interconnector is provided for connecting an RF power supply to electrodes contained in the shielded, hermetically sealed laser tube housing of a slab laser system. The impedance matching interconnector comprises a short length of co-axial conductor and an impedance matching network that includes two L shaped networks. The inner conductor of the co-axial conductor is connected between the power supply output and the…
Adjustable pulse-shaper
Granted: June 2, 2009
Patent Number:
7542192
An optical pulse-shaper includes a prism, a delay line having positive optical power and a reflective spatial light modulator. In one arrangement the delay line has a selectively variable optical path length for accommodating pulses of different spectral bandwidth and positive optical power is provided by a concave mirror. In another arrangement, the delay line includes a zoom-mirror arranged to provide selectively variable optical power for accommodating pulses of different spectral…
Efficient lidar with flexible target interrogation pattern
Granted: May 12, 2009
Patent Number:
7532311
A system for observing a field of view including a light transmitter and a light detector. A path is defined between the transmitter and the detector. The light transmitter generates substantially coherent light onto a transmit portion of a light path and the light detector is positioned in a receive portion of the light path defined by reflected light from some of the target locations. The system includes a component for configuring at least a portion of the light path such that a…
High power and high brightness diode-laser array for material processing applications
Granted: April 7, 2009
Patent Number:
7515346
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…
Sub-millimeter wave frequency heterodyne detector system
Granted: March 24, 2009
Patent Number:
7507963
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.
Double-pass fiber amplifier
Granted: March 24, 2009
Patent Number:
7508579
Several examples of double-pass fiber amplifiers including a polarization maintaining (PM) gain-fiber are disclosed. In each example, input and twice-amplified output are separated by an all-fiber, polarization-maintaining polarization splitter combiner. In one example, light is first passed through a gain fiber in a first polarization direction and then is passed through the gain fiber in a second polarization direction. The light exits the splitter combiner in the first polarization…
Apparatus for modifying COslab laser pulses
Granted: March 24, 2009
Patent Number:
7508850
The quality of pulses output from laser systems such as super-pulsed CO2 slab lasers can be improved using half-wavelength electro-optic modulators (EOMs), in combination with thin film polarizers (TFPs). A voltage applied across a CdTe crystal of the EOM rotates the polarization of a pulse passing through the EOM by 90°. The polarization determines whether the pulse passes through, or is redirected by, the TFP. The voltage applied to the crystal can be pulsed to prevent a drop in…
Frequency-converted high-power laser with recirculating polarization control
Granted: March 17, 2009
Patent Number:
7505491
A frequency-tripled laser-resonator has three resonator-branches. The branches are optically connected with each other by one or more polarization-selective devices. Unpolarized fundamental radiation is generated by optically pumping a gain-element in one branch of the resonator. The polarization-selective device provides that radiation in the other branches is plane-polarized, with the polarization planes of radiation entering the branches perpendicular to each other. Two optically…
Thermally tuned diode-laser bar package
Granted: March 10, 2009
Patent Number:
7502398
A directly cooled diode-laser bar package includes a diode-laser bar bonded to a heat-sink. The operating temperature of the diode-laser bar can be selectively varied by varying the thermal impedance of the heat-sink in or near a region of the heat-sink on which the diode-laser bar is bonded. The thermal impedance is selectively varied by varying the insertion depth of screws inserted into corresponding screw holes extending into the heat-sink close to or immediately adjacent the region…
