Coherent, Inc.

Norman Hodgson

Dmitri Simanovski

Andrei Starodoumov

H Yang Pang

Michael Hertwig

Andrea Caprara

Gary Y Wang

R Russel Austin

Luis A Spinelli

Andrei Staroudoumov

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

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.

Optical parametric chirped-pulse amplifier

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 resonator. The optical length of the linear fiber resonator is an integer multiple of the optical length of the fiber branch. The repetition rate of the ultrashort laser pulses is the reciprocal of the propagation time of the laser pulses through the fiber branch.

High repetition rate seed laser

An apparatus for generating visible light including a laser source emitting a fundamental beam, an optically nonlinear crystal, and a seed source emitting a seed beam. The optically nonlinear crystal receives the fundamental beam. The fundamental beam propagates in the nonlinear crystal at a first phase-matching angle for second-harmonic generation. A portion of the fundamental beam is converted into a second-harmonic beam that propagates in the nonlinear crystal at the first phase-matching angle for optical parametric generation. The seed source emits a seed beam having a wavelength longer than the second-harmonic beam. The seed beam is directed into the nonlinear crystal and propagates at a second phase-matching angle for the optical parametric amplification. A portion of the second-harmonic beam is converted into a signal beam at the seed wavelength and an idler beam by the optical parametric amplification.

Single Crystal optical parametric amplifier

Laser-apparatus includes a fiber-MOPA arranged to deliver amplified seed optical pulses having a wavelength of about 1043 nanometers to a multi-pass ytterbium-doped yttrium aluminum garnet solid-state optical amplifier for further amplification.

High power sub-400 femtosecond MOPA with solid-state power amplifier

Plane-polarized laser-radiation from a laser-source is converted to circularly polarized radiation by a quarter-wave plate. The circularly polarized radiation is input into a hollow-core fiber for transport to a point of use. The transported radiation is converted back to plane-polarized radiation by another quarter-wave plate between the fiber and the point of use.

Transport of polarized laser-radiation using a hollow-core fiber

A source of femtosecond pulses at center wavelengths of about 940 nm and about 1140 nanometers (nm) includes a mode-locked fiber MOPA delivering pulses having a center wavelength of about 1040 nm. The 1040-nanometer pulses are spectrally spread into a continuum spectrum extending in range between about 900 nm and about 1200 nm and having well defined side-lobes around the 940-nm and 1140-wavelengths. Radiation is spatially selected from these side-lobes and delivered as the 940-nm and 1140-nm pulses.

Multi-wavelength source of femtosecond infrared pulses

A mode-locked fiber MOPA delivers pulses of laser-radiation. A super-continuum generator including a bulk spectral-broadening element and a negative group-delay dispersion (NGDD) device is arranged to receive a pulse from the MOPA and cause the pulse to make a predetermined number of sequential interactions with the broadening element and the NGDD device. After making the predetermined interactions, the pulse is delivered from the super-continuum generator with a very broad spectral-bandwidth and a very short duration.

Tunable femtosecond laser-pulse source including a super-continuum generator

Pulses from a mode-locked Yb-doped laser () are spectrally broadened in an optical fiber (), and temporally compressed in a grating compressor (), then frequency-doubled () and used to pump an optical parametric oscillator (OPO) (). The OPO output is tunable over a wavelength range from about 600 nm to about 1100 nm. Mode-locking in the Yb-doped laser () is accomplished with a SESAM () or by Kerr-lens mode-locking with a Kerr medium () and a hard aperture ().

Optical parametric oscillator pumped by femtosecond thin-disk laser

A laser includes a Ti:sapphire gain-medium in the form of a thin-disk. The thin-disk gain-medium is optically pumped by pump-radiation pulses having a wavelength in the green region of the electromagnetic spectrum. The pump-radiation pulses have a duration less than twice the excited-state lifetime of the gain-medium.

Transition-metal-doped thin-disk laser

An optical amplifier for use as a final amplification stage for a fiber-MOPA has a gain-element including a thin wafer or chip of ytterbium-doped YAG. An elongated gain-region is formed in gain-element by multiple incidences of radiation from a diode-laser bar.

High-gain face-pumped slab-amplifier

A master oscillator power-amplifier stages includes multiple stages of fiber-amplification with a final power amplifier stage in the form of a multi-pass amplifier. With a thin-disk gain medium in one example the thin-disk amplifier includes a common optical arrangement for providing multiple incidences of radiation to be amplified and multiple incidences of a pump-radiation beam on the thin-disk gain medium.

Hybrid fiber-MOPA

Pulses from a mode-locked Yb-doped laser are spectrally broadened, and temporally compressed, then frequency-doubled and used to pump an optical parametric oscillator (OPO). The OPO output is tunable over a wavelength range from about 600 nm to about 1100 nm.

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Belmont, CA, United States of America

Norman Hodgson