LASER WELDING METHOD
Granted: November 25, 2021
Application Number:
20210362271
A method for laser keyhole welding is disclosed to weld two pieces together made of a metal alloy. The method independently adjusts power in a focused center beam and power in a concentric focused annular beam. At the termination of a weld, the power of the annular beam is reduced, motion of the focused beams is stopped, the power of the center beam is increased, and the power of both beams is initially ramped down rapidly and then ramped down slowly. Increasing the power of the center…
SECOND-HARMONIC GENERATION CRYSTAL
Granted: August 26, 2021
Application Number:
20210265802
An optic produces a beam of ultraviolet laser radiation from a beam of visible laser radiation and spatially separates the ultraviolet laser beam from the visible laser beam. The optic includes two crystals made of the same optically-nonlinear material that are contact bonded along a planar interface. One crystal has principle crystal axes that are oriented for type-I second-harmonic generation. The ultraviolet laser beam exits the optic through an uncoated surface of the other crystal.…
RADIO-FREQUENCY EXCITED GAS LASER
Granted: August 5, 2021
Application Number:
20210242650
A radio-frequency excited carbon dioxide (CO2) or carbon monoxide (CO) gas laser includes two electrodes, which have passivated surfaces, within a sealed housing. Features in a ceramic slab or a ceramic cylinder located between the electrodes define a gain volume. Surfaces of the ceramic slab or the ceramic cylinder are separated from the passivated surfaces of the electrodes by small gaps to prevent abrasion thereof. Reducing compressive forces that secure these components within the…
SPECTRAL SENSOR SYSTEM EMPLOYING A DEEP LEARNING MODEL FOR SENSING LIGHT FROM ARBITRARY ANGLES OF INCIDENCE, AND RELATED HYPERSPECTRAL IMAGING SENSOR
Granted: March 11, 2021
Application Number:
20210072081
A spectral sensing system includes an array of sampling optical elements (e.g. filters) and an array of optical sensors, and a deep learning model used to process output of the optical sensor array. The deep learning model is trained using a training dataset which includes, as training inputs, optical sensor output generated by shining each one of multiple different light waves with known spectra on the sampling optical element array for multiple different times, each time from a known…
OPTICAL PARAMETRIC CHIRPED-PULSE AMPLIFIER
Granted: February 25, 2021
Application Number:
20210057868
An optical parametric chirped-pulse amplifier includes first and second optical parametric amplifier stages that successively amplify a stretched signal beam. A pulsed laser provides a fundamental beam. The second amplifier stage is pumped by the full power of a second-harmonic beam that is generated from the fundamental beam. A residual fundamental beam is used to generate another second-harmonic beam that pumps the first amplifier stage.
LASER WAVELENGTH STABILIZATION APPARATUS
Granted: January 28, 2021
Application Number:
20210028599
A wavelength sensor for wavelength stabilization of a laser beam includes an etalon placed in the laser beam and tilted with respect to the laser beam. Reflected beams from the etalon form an interference pattern on a segmented photodetector having two detector segments. Output signals from the two detector segments are used to derive an error signal for a closed control loop to effect the wavelength stabilization.
HIGH REPETITION RATE SEED LASER
Granted: December 10, 2020
Application Number:
20200388983
A fiber laser producing a beam of ultrashort laser pulses at a repetition rate greater than 200 MHz includes a linear fiber resonator and a fiber branch. Ultrashort laser pulses are generated by passive mode-locking and circulate within the linear fiber resonator. Each circulating laser pulse is split into a portion that continues propagating in the linear fiber resonator and a complementary portion that propagates through the fiber branch and is then returned to the linear fiber…
HIGH DYNAMIC RANGE OPTICAL SENSING DEVICE EMPLOYING BROADBAND OPTICAL FILTERS INTEGRATED WITH LIGHT INTENSITY DETECTORS
Granted: October 29, 2020
Application Number:
20200344430
A high dynamic range image sensors enabled by integrating broadband optical filters with individual sensor pixels of a pixel array. The broadband optical filters are formed of engineered micro or nanostructures that exhibit large differences in transmittance, e.g. up to 5 to 7 orders of magnitude. Such high transmittance difference can be achieved by using a single layer of individually designed filters, which show varied transmittance as a result of the distinct absorption of various…
BEAM FORMING WITH FOCUS LOCATION ADJUSTMENT
Granted: October 29, 2020
Application Number:
20200341286
An apparatus includes a beam source, beam forming optics, a first focusing lens having a focal length, a second focusing lens having a focal length similar to the focal length of the first lens, and a lens translator configured to move the second lens transversely relative to the beam forming optics and to the first lens, and thereby move the elongated focus transversely. In some embodiments, the beam forming optics are positioned between the beam source and the first focusing lens, the…
EXCIMER LASER WITH UNIFORM BEAM
Granted: September 24, 2020
Application Number:
20200303889
Fine-structure in the transverse mode of an excimer laser beam is minimized by having a plurality of resonator mirrors located at each end of a linear excimer laser. At one end, a highly-reflective end mirror and a partially-reflective end mirror are inclined at small angle with respect to each other. At the other end, two output-coupling mirrors are inclined at a small angle with respect to each other. This arrangement of resonator mirrors generates a composite laser beam that blurs any…
OPTICAL SENSING DEVICE EMPLOYING LIGHT INTENSITY DETECTORS INTEGRATED WITH NANOSTRUCTURES
Granted: September 24, 2020
Application Number:
20200301053
Optical sensing devices employing light intensity detectors integrated with nanostructures. In some embodiments, the nanostructures are 3D nanostructures having feature sizes in all three dimensions comparable to a wavelength range of the incident light, and are used for hyperspectral sensing. In some other embodiments, the nanostructures are simultaneous sensitive to both the spectrum and one or more of polarization, angle and phase information of the incident light field, to provide…
APPARATUS FOR FORMING A HOMOGENEOUS INTENSITY DISTRIBUTION WITH BRIGHT OR DARK EDGES
Granted: September 17, 2020
Application Number:
20200292836
A beam homogenizer for transforming a beam of laser-radiation into a flat-top intensity distribution having brighter or darker edges comprises a first lens array, a second lens array, and a positive lens. The first lens array includes a plurality of lens elements that are separated by gaps having no optical power. Brighter or darker edges are produced by selecting a distance between the first and second lens arrays that is less than or greater than the focal length of lens elements in…
LASER APPARATUS FOR CUTTING BRITTLE MATERIAL
Granted: August 13, 2020
Application Number:
20200254564
An apparatus for cutting brittle material comprises an aspheric focusing lens, an aperture, and a laser-source generating a beam of pulsed laser-radiation. The aspheric lens and the aperture form the beam of pulsed laser-radiation into an elongated focus having a uniform intensity distribution along the optical axis of the aspheric focusing lens. The elongated focus extends through the full thickness of a workpiece made of a brittle material. The workpiece is cut by tracing the optical…
LASER WELDING METHOD
Granted: August 13, 2020
Application Number:
20200254562
A method for laser keyhole welding of metal alloys is disclosed. The method independently adjusts power in a focused center beam and power in a concentric focused annular beam. At the termination of a weld, the power in the center beam is initially ramped up and then ramped down, while the power in the annular beam is ramped down. Increasing the power in the center beam enables a controlled and prolonged contraction of the keyhole and melt pool, thereby preventing undesirable cracking.
DIODE-PUMPED SOLID-STATE LASER APPARATUS FOR LASER ANNEALING
Granted: July 23, 2020
Application Number:
20200235544
Laser annealing apparatus includes a plurality of frequency-tripled solid-state lasers, each delivering an output beam of radiation at a wavelength between 340 nm and 360 nm. Each output beam has a beam-quality factor (M2) greater of than 50 in one transverse axis and greater than 20 in another transverse axis. The output beams are combined and formed into a line-beam that is projected on a substrate being annealed. Each output beam contributes to the length of the line-beam.
CONDUCTIVELY-COOLED SLAB LASER
Granted: July 23, 2020
Application Number:
20200235542
A carbon dioxide gas-discharge slab-laser is assembled in a laser-housing. The laser-housing is formed from a hollow extrusion. An interior surface of the extrusion provides a ground electrode of the laser. Another live electrode is located within the extrusion, electrically insulated from and parallel to the ground electrode, forming a discharge-gap of the slab-laser. The electrodes are spaced apart by parallel ceramic strips. Neither the extrusion, nor the live electrode, include fluid…
THIRD-HARMONIC GENERATING APPARATUS FOR LASER-RADIATION
Granted: April 30, 2020
Application Number:
20200132906
A third-harmonic conversion arrangement includes a second-harmonic generating crystal and a third-harmonic generating crystal arranged in a polarization loop. The polarization loop causes plane-polarized fundamental-wavelength radiation being converted to make two passes through the crystals in orthogonally-opposed polarization orientations.
MITIGATING LOW SURFACE QUALITY
Granted: February 27, 2020
Application Number:
20200061750
Methods and apparatuses are disclosed for laser processing. A method includes providing a laser beam transparent to a workpiece. A cover, having a surface quality better than the workpiece's surface, is provided and spaced apart from the workpiece's surface. A fluid is provided between and in contact with the cover and the workpiece's surface. A laser beam is directed through the cover and fluid to the workpiece. An apparatus includes a cover spaced apart from a workpiece's surface and…
SEPARATION AND RELEASE OF LASER-PROCESSED BRITTLE MATERIAL
Granted: January 30, 2020
Application Number:
20200030917
A method for separating and releasing a closed-form piece from a workpiece made of a brittle material is disclosed. A first pulsed laser-beam creates defects along the outline of the closed-form piece. A second laser-beam selectively heats the closed-form piece for a first time that is sufficient to initiate cracking between the defects. The heating is stopped for a period sufficiently long for the cracks to propagate completely between the defects. The second laser-beam is applied for a…
LASER-MOPA WITH BURST-MODE CONTROL
Granted: December 19, 2019
Application Number:
20190386450
A laser master-oscillator power-amplifier (MOPA) is operated to provide successive bursts of ultrashort pulses. The pulse-bursts are selected by an optical modulator from a pulse train delivered by the master oscillator prior to amplification in the power amplifier. The optical modulator has a selectively variable transmission specified by an analog voltage signal having a stepped waveform. The voltage signal is delivered by a sequentially-switched parallel switch-array connected in…
