Abstract: A laser system includes a plurality of diode lasers, a cryogenic cooling system circulating a cryogenic coolant and coupled to the plurality diode lasers to cool the plurality of diode lasers with the cryogenic coolant, and a fuel cell coupled to the plurality of diode lasers to power the plurality of diode lasers and situated to receive the cryogenic coolant from the cryogenic cooling system as fuel for the fuel cell. A method of operating a high power laser system includes cooling a plurality of diode lasers with a cryogenic cooling system circulating a cryogenic coolant, fueling a fuel cell with a portion of the cryogenic coolant circulating in the cryogenic cooling system, and powering the plurality of diode lasers with power generated by the fuel cell.

Abstract: A system includes an optical fiber situated to propagate a laser beam received from a laser source to an output of the optical fiber, a first cladding light stripper optically coupled to the optical fiber and situated to extract at least a portion of forward-propagating cladding light in the optical fiber, and a second cladding light stripper optically coupled to the optical fiber between the first cladding light stripper and the optical fiber output and situated to extract at least a portion of backward-propagating cladding light in the optical fiber.

Abstract: Seed pulse generators for fiber amplifier systems include a seed pump controller coupled to a seed pump laser diode. A photodetector is situated to detect seed pulse generation, and is coupled to the seed pump controller so that seed pumping is decreased upon pulse detection. For a laser diode pump source, a pump current can be pulsed to produce a seed pulse and then decreased to a bias level such as a DC bias current that is less than a pump laser threshold current. Single seed pulses can be generated with reduced pulse jitter.

Abstract: A laser marking method and system, and laser marked object are disclosed. The method includes directing a pulsed laser beam towards an object such that an interface between an anodized layer and non-anodized substrate is in a mark zone of the pulsed laser beam, and scanning the pulsed laser beam across the object in a predetermined pattern to create a mark having an L value of less than 35 and a surface roughness that is substantially unchanged compared to adjacent unmarked areas. The system includes a fiber laser generating amplified pulses that are directed towards a galvo-scanner and focusing optic, while the object includes an anodized surface layer, an underlying non-anodized substrate, and a mark having an L value of less than 35 with substantially unchanged roughness features.

Abstract: An optical apparatus includes one or more pump sources situated to provide laser pump light, and a gain fiber optically coupled to the one or more pump sources, the gain fiber including an actively doped core situated to produce an output beam, an inner cladding and outer cladding surrounding the doped core and situated to propagate pump light, and a polymer cladding surrounding the outer cladding and situated to guide a selected portion of the pump light coupled into the inner and outer claddings of the gain fiber. Methods of pumping a fiber sources include generating pump light from one or more pump sources, coupling the pump light into a glass inner cladding and a glass outer cladding of a gain fiber of the fiber source such that a portion of the pump light is guided by a polymer cladding surrounding the glass outer cladding, and generating a single-mode output beam from the gain fiber.

Abstract: A high power diode laser module is provided with improved high temperature handling and reliability, the module including a housing made of a thermally conductive material and providing a module interior extending between a plurality of housing surfaces, at least one diode laser disposed in the module interior and situated to emit a laser beam, one or more optical components disposed in the module interior and coupled to the at least one diode laser so as to change one or more characteristics of the laser beam, a waveguide in optical communication with the module interior and situated to receive the laser beam from the one or more optical components, and an optical absorber disposed in the housing and situated to receive stray light which is associated with the laser beam and which is propagating in the module interior so as to absorb the stray light and conduct heat associated with the stray light away from the module interior and into the housing.

Abstract: A fiber termination assembly includes an optical fiber inserted into an optical ferrule disposed in an optical passageway of a heat conductive housing, the optical passageway providing an optical path aligned with the openings of the housing, the optical ferrule including a central bore concentrically disposed about the optical path and configured to receive a portion of a proximal end of the optical fiber therein, the optical ferrule and optical fiber secured in relation to the heat conductive housing with epoxy at a distal end of the optical ferrule, wherein the optical ferrule is transparent at a predetermined wavelength of light such that for light coupled into an input surface of the proximal end of the optical fiber at least a portion of the light propagating as cladding modes is stripped out of the optical fiber and transported to and dissipated in the heat conductive housing.

Abstract: A high brightness diode laser package includes a plurality of flared laser oscillator waveguides arranged on a stepped surface to emit respective laser beams in one or more emission directions, a plurality of optical components situated to receive the laser beams from the plurality of flared laser oscillator waveguides and to provide the beams in a closely packed relationship, and an optical fiber optically coupled to the closely packed beams for coupling the laser beams out of the diode laser package.

Abstract: A laser diode apparatus including a diode laser, optics efficiently collimate the diode laser beam, and a narrow band reflector to provide optical feedback for wavelength stabilization of the diode laser in an extended cavity configuration. The extended cavity laser diode assembly has a low reflectivity coating applied to the front facet, and a narrow-band reflectivity engineered to optimize the output power from the diode laser, leading to power penalty-free operation of the extended cavity laser diode assembly as compared to a free-running diode laser. The extended cavity laser diode assembly can equally applied to a plurality of laser diodes, with either a single or a plurality of optical feedback devices forming the extended cavity configuration.

Abstract: An example apparatus includes an optical fiber including a core and cladding, the core being situated to propagate an optical beam along a propagation axis associated with the core, and at least one fiber Bragg grating (FBG) situated in the core of the optical fiber, the fiber Bragg grating including a plurality of periodically spaced grating portions situated with respect to the propagation axis so that light associated with Raman scattering is directed out of the core so as to reduce the generation of optical gain associated with stimulated Raman scattering (SRS).

Abstract: A broad area semiconductor diode laser device includes a multiple flared oscillator waveguide including a plurality of component flared oscillator waveguides, each component flared oscillator waveguide including a multimode high reflector facet, a partial reflector facet spaced apart from the high reflector facet, and a flared current injection region extending and widening between the multimode high reflector facet and the partial reflector facet, wherein the ratio of a partial reflector facet width to a high reflector facet width is n:1, where n>1, and wherein the component flared oscillator waveguides of the multiple flared oscillator waveguide are arranged in a row such that portions of the flared current injection regions of adjacently situated component flared oscillator waveguides overlap each other or are in proximity to each other on the order of the wavelength of light emitted by the component flared oscillator waveguides.

Abstract: A laser marking method and system, and laser marked object are disclosed. The method includes directing a pulsed laser beam towards an object such that an interface between an oxidized layer and non-oxidized substrate is in a mark zone of the pulsed laser beam, and scanning the pulsed laser beam across the object in a predetermined pattern to create a mark having an L value of less than 40 and a surface roughness that is substantially unchanged compared to adjacent unmarked areas. The system includes a fiber laser generating amplified pulses that are directed towards a galvo-scanner and focusing optic, while the object includes an oxidized surface layer, an underlying non-oxidized substrate, and a mark having an L value of less than 40 with substantially unchanged roughness features.

Abstract: Nonlinear optical systems include fiber amplifiers using tapered waveguides such as optical fibers that permit multimode propagation but produce amplification and oscillation in a fundamental mode. The tapered waveguides generally are provided with an active dopant that is pumped with an optical pump source such as one or more semiconductor lasers. The active waveguide taper is selected to taper from a single or few mode section to a multimode section, and a seed beam in a fundamental mode is provided to a section of the waveguide taper associated with a smaller optical mode. An amplified beam exits the waveguide taper at a section associated with a larger optical mode. The amplified beam is directed to nonlinear conversion optics such as one or more nonlinear crystals to produce high peak power and high beam quality converted light using second or third harmonic generation, or other nonlinear processes.

Abstract: A laser system includes a laser resonator having a laser resonator volume and a gain block disposed therein, the gain block being configured to emit light at a predetermined laser wavelength, and an OPO unstable resonator having an OPO unstable resonator volume, the OPO unstable resonator optically coupled to the laser resonator and configured to receive light therefrom, wherein a portion of the OPO unstable resonator volume is situated with respect to the laser resonator volume so as to form an overlapping volume.

Abstract: A multi-wavelength semiconductor diode laser device includes a semiconductor diode gain medium including one or more quantum well structures, each of the quantum well structures having an associated gain peak, the semiconductor gain medium further including a back facet configured for high reflection of laser light therein and a front facet configured for coupling a laser beam therefrom, one or more collimation optics configured to receive the laser beam, and an external volume Bragg grating configured to reflect a portion of the laser beam and narrow the wavelength of at least a portion of the light generated by the semiconductor gain medium to a selected wavelength corresponding to at least one of the gain peaks, wherein an output beam is coupled out of the external volume Bragg grating, the output beam having a plurality of output wavelengths.

Abstract: A process measurement system for measuring a parameter of a work surface includes a light source configured to provide a material processing beam, an optical delivery system optically coupled to the light source and configured to homogenize and direct the material processing beam to the work surface, the optical delivery system including a process optic for optically coupling the material processing beam to the work surface in a predetermined way, the optical delivery system including a delivery waveguide having an output face optically coupled to the process optic, and an optical pyrometer in optical communication with the optical delivery system and configured to receive a pyrometer signal emitted from the work surface and coupled into said output face.

Abstract: Pulse power can be stabilized by applying spectrally narrow pulses to a laser diode during gain switching. An injection locking laser with a narrow emission bandwidth is tuned to a gain bandwidth of a laser diode to be gain switched. The injection locking emission is pulsed to provide locking pulses that are attenuated and then coupled to a laser diode. A gain switching pulse drive is applied to the laser diode in the presence of the attenuated locking pulses. The gain switched output is then stabilized with respect to pulse energy and pulse amplitude, and is suitable as a seed pulse for lasers to be used in materials processing.

Abstract: A broad area semiconductor diode laser device includes a multimode high reflector facet, a partial reflector facet spaced from said multimode high reflector facet, and a flared current injection region extending and widening between the multimode high reflector facet and the partial reflector facet, wherein the ratio of a partial reflector facet width to a high reflector facet width is n:1, where n>1. The broad area semiconductor laser device is a flared laser oscillator waveguide delivering improved beam brightness and beam parameter product over conventional straight waveguide configurations.

Abstract: A processing system directs a laser beam to a composite including a substrate, a conductive layer, and a conductive border. The location of a focus of the laser beam can be controlled to bring the laser beam into focus on the surfaces of the conductive materials. The laser beam can be used to ablatively process the conductive border and non-ablatively process the conductive layer by translating a focus-adjust optical system so as to vary laser beam diameter.

Abstract: A method of non-ablatively laser patterning a multi-layer structure, the multi-layer structure including a substrate, a first layer disposed on the substrate, a second layer disposed on the first layer, and a third layer disposed on the second layer, the method including generating at least one laser pulse having laser parameters selected for non-ablatively changing the conductivity a selected portion of the third layer such that the selected portion becomes non-conductive, and directing the pulse to the multi-layer structure, wherein the conductivity of the first layer is not substantially changed by the pulse.