Coherent, Inc.

Coherent Lasersystems Gmbh & Co. Kg

Helios Photonics, Inc.

Andrea Caprara

Luis A Spinelli

Juan L Chilla

Sergei V Govorkov

R Russel Austin

Norman Hodgson

Murray Keith Reed

Qi-Ze Shu

Stuart Butterworth

Ian MacGillivray

Andrei Staroudoumov

Rui Zhang

Serguei Anikitchev

Stephen P Boyd

Michael Hertwig

Gary Y Wang

Michele Wayne Winz

Arnaud Lepert

Frank Simon

Briggs Atherton

Ludwig Schwenger

Christopher Ihli

Derek U Gerlach

Kai Schmidt

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 (M) 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.

Diode-pumped solid-state laser apparatus for laser annealing

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 the second lens array.

Apparatus for forming a homogeneous intensity distribution with bright or dark edges

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, which includes a plurality of mirrors, a polarization-selective reflector, and a polarization rotator, causes plane-polarized fundamental-wavelength radiation being converted to make two passes through the crystals in orthogonally-opposed polarization orientations.

Third-harmonic generating apparatus for laser-radiation having polarization loop

A fiber-laser includes a gain-fiber in a laser-resonator. A polarizer is located in the laser-resonator at an end thereof, causing the output of the fiber-laser to be linearly polarized. A wavelength-selective element is also included in the laser-resonator for selecting an output wavelength of the fiber-laser from within a gain-bandwidth of the gain-fiber.

Polarized fiber-laser

A mirror is used to form a beam of laser-radiation having a uniform intensity distribution from a beam of laser-radiation having a non-uniform intensity distribution. The mirror has a reflective surface that has a compound shape, which is two inclined surfaces joined by a rounded apex. The compound-mirror is achromatic and can form a uniform intensity distribution from a polychromatic beam of laser-radiation. The uniform intensity distribution may be an isotropic distribution or a flat-top distribution in a plane. The non-uniform intensity distribution may be a Gaussian distribution from a laser source.

Reflective laser line-beam generator

Apparatus for generating a line-beam includes a diode-laser bar, a linear micro-lens array, and a plurality of lenses spaced apart and arranged along an optical axis. The linear micro-lens array and the lenses shape laser-radiation emitted by the diode-laser bar to form a uniform line-beam in an illumination plane. The lenses project a far-field image of the diode-laser bar onto an image plane proximate to the illumination plane. The diode-laser bar is rotated from parallel alignment with the linear micro-lens array for providing uniform line-beam illumination over a range of locations along the optical axis.

Apparatus for generating a line-beam from a diode-laser array

A laser includes an optically pumped semiconductor OPS gain-structure. The apparatus has a laser-resonator which includes a mode-locking device for causing the laser to deliver mode-locked pulses. The resonator has a total length selected such that the mode-locked pulses are delivered at a pulse repetition frequency less than 150 MHz. An optical arrangement within the resonator provides that radiation circulating in the resonator makes a plurality of incidences on the OPS gain-structure with a time less than the excited-state lifetime of the gain-structure between successive incidences.

Mode-locked optically pumped semiconductor laser

An optical parametric oscillator includes one unidirectional enhancement resonator for optical pump-radiation and a second unidirectional resonator at least partially coaxial with the enhancement resonator. An optically nonlinear crystal is located in the coaxial portion of the resonators and converts the optical pump-radiation to signal radiation having a wavelength longer than that of the pump radiation and idler radiation having a wavelength longer than that of the signal radiation. The second resonator resonates the signal-wavelength radiation and delivers a fraction of that radiation as output radiation.

Optical parametric oscillator with embedded resonator

A ring laser-resonator generating plane-polarized fundamental-frequency radiation includes an optically nonlinear crystal configured for type-II second-harmonic generation of fundamental-frequency radiation. The resonator is configured such that fundamental-frequency radiation circulating either clockwise or counter-clockwise therein makes two passes through the optically nonlinear crystal per round-trip in the resonator in opposite directions, with polarization planes perpendicular to each other. This arrangement forces unidirectional circulation of radiation in the resonator during which second-harmonic radiation is not generated by the crystal.

Traveling-wave ring-oscillators without a faraday rotator

A laser includes an optically pumped semiconductor OPS gain-structure. The apparatus has a laser-resonator which includes a mode-locking device for causing the laser to deliver mode-locked pulses. The resonator has a total length selected such that the mode-locked pulses are delivered at a pulse repetition frequency of about 100 MHz. An optical arrangement within the resonator provides that radiation circulating in the resonator makes a plurality of incidences on the OPS gain-structure with a time less than the excited-state lifetime of the gain-structure between successive incidences.

A solid state-gain medium is in the form of a thin disk backed by a reflective coating. A laser resonator is formed by the reflective coating and another mirror. Optical pump radiation is directed into the thin-disk gain-medium for energizing the gain-medium and generating a standing wave of fundamental-wavelength radiation in the resonator. The pump-radiation is directed into the gain-medium at an angle to the resonator axis and pump-radiation fringes are formed by interference between incident and reflected pump-radiation. The pump-radiation angle is selected such that the pump-radiation fringes are aligned with antinodes of the fundamental-wavelength standing wave.

Single-mode intra-cavity frequency-doubled CW solid-state laser with volumetric gain-grating

In a branched resonator OPS-laser arrangement, a combination of intra-cavity optical parametric generation and intra-cavity frequency conversion provides output radiation in a range between about 550 nanometers about 800 nanometers from an OPS fundamental wavelength in a range between about 900 nm and about 1100 nm.

Intracavity frequency-converted optically-pumped semiconductor optical parametric oscillator

A laser includes a traveling-wave ring-resonator in which one resonator mirror is a mirror of an interferometer arranged such that, when the interferometer is operated in an anti-resonant condition, the mirror has a greater effective reflectivity for clockwise circulation of light in the resonator than for anticlockwise circulation of light in the resonator. There is a difference between the clockwise and anticlockwise effective-reflectivity sufficient that lasing in the resonator is possible only in the clockwise direction.

Traveling-wave laser having a resonator including a direction-sensitive interferometer for establishing unidirectional circulation

In a branched resonator OPS-laser arrangement, a combination of intra-cavity optical parametric generation and intra-cavity sum-frequency mixing provides output radiation in a range between about 550 nanometers about 700 nanometers from an OPS fundamental wavelength in a range between about 900 nm and about 1100 nm.

Intracavity frequency-converted optically-pumped semiconductor laser with red-light output

An optically pumped semiconductor-laser (OPS-laser) resonator includes an arrangement for delivering optical pump radiation on an OPS-chip to cause fundamental radiation to circulate in the resonator. The resonator includes second and third-harmonic generating crystals and is arranged deliver third-harmonic radiation. The resonator also includes a stop positioned and configured to stabilize the laser output. The pump radiation arrangement delivers the pump radiation at an angle to the resonator axis and includes wedged GRIN lens arranged such that the pump radiation forms a circular spot on the OPS chip. The third harmonic generating crystal acts as a polarizer for the fundamental radiation and angularly separates fundamental and third harmonic beams.

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Palo Alto, CA, United States of America

Andrea Caprara