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: Multimode beam combiners include at least one gradient-step index optical fiber in which a refractive index difference at a core/cladding interface is selected to provide a numerical aperture so as to provide stable, uniform beam output. One or more such fibers is formed into a tapered bundle than can be shaped to provide a selected illuminated aperture. The fibers in the bundle can be separated by respective tapered claddings so as to be optically coupled or uncoupled. Illumination systems can include a plurality of such fibers coupled to a plurality of laser diodes or other light sources.

Abstract: Single mode fiber beam combiners are formed by extending single mode fibers through a glass ferrule, and tapering and fusing the fibers and the ferrule. Tapers can be selected so that optical power input to each of the single mode fibers remains partially guided by the single mode fiber cladding, or is guided by the multimode fiber formed by the glass ferrule and the fused fiber claddings. Such combiners can include double clad fibers or actively doped fibers for use in lasers or amplifiers.

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: 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: Fiber amplifiers and oscillators include 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 such as a rare earth element 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 seed beam in a fundamental mode is provided to a section of the waveguide taper associated with a smaller optical mode, and an amplified beam exits the waveguide taper at a section associated with a larger optical mode.

Abstract: Multimode beam combiners include at least one gradient-step index optical fiber in which a refractive index difference at a core/cladding interface is selected to provide a numerical aperture so as to provide stable, uniform beam output. One or more such fibers is formed into a tapered bundle than can be shaped to provide a selected illuminated aperture. The fibers in the bundle can be separated by respective tapered claddings so as to be optically coupled or uncoupled. Illumination systems can include a plurality of such fibers coupled to a plurality of laser diodes or other light sources.

Abstract: Scribing operations with reduced substrate heating can be provided by applying multiple optical pulses to a substrate within a time interval that is less than a material recombination time. Typically a series of pulses of durations of 5-200 ps with pulse energies of less than about 0.002 mJ can be applied at rates of about 1 MHz to about 30 MHz. Beam area and beam scanning are configured to provide substantial overlap so that material can be removed by cold ablation.

Abstract: Hybrid laser systems include fiber amplifiers using tapered waveguides and solid-state amplifiers. Typically, such systems represent a technically simple and low cost approach to high peak power pulsed laser systems. The tapered waveguides generally are provided with an active dopant such as a rare earth element that is pumped with one or more semiconductor lasers. The active waveguide taper is selected to taper from a single or few mode section to a multimode section. A seed beam in a fundamental mode is provided to a section of the waveguide taper associated with a smaller optical mode, and an amplified beam exits the waveguide taper at a section associated with a larger optical mode. The waveguide taper permits amplification to higher peak power values than comparable small mode area fibers. The fiber amplified beam is then directed to a solid state amplifier, such as a thin disk or rod-type laser amplifier.

Abstract: A stable, single mode fiber amplifier is described. The amplifier consists of a seed source, a passive single clad multimode fiber, an active double clad multimode fiber or a multimode fiber horn and a semiconductor laser pump source. The passive fiber is packaged on a mandrel with a compound radius of curvature such that high order modes in the fiber are stripped from the core leaving only the fundamental mode. This fiber is then spliced to a multimode active fiber of similar core diameter. By exciting only the fundamental mode of this active fiber, stable single mode amplification is achieved.

Abstract: Hybrid laser systems include fiber amplifiers using tapered waveguides and solid-state amplifiers. Typically, such systems represent a technically simple and low cost approach to high peak power pulsed laser systems. The tapered waveguides generally are provided with an active dopant such as a rare earth element that is pumped with one or more semiconductor lasers. The active waveguide taper is selected to taper from a single or few mode section to a multimode section. A seed beam in a fundamental mode is provided to a section of the waveguide taper associated with a smaller optical mode, and an amplified beam exits the waveguide taper at a section associated with a larger optical mode. The waveguide taper permits amplification to higher peak power values than comparable small mode area fibers. The fiber amplified beam is then directed to a solid state amplifier, such as a thin disk or rod-type laser amplifier.

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: Fiber amplifiers and oscillators include 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 such as a rare earth element 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 seed beam in a fundamental mode is provided to a section of the waveguide taper associated with a smaller optical mode, and an amplified beam exits the waveguide taper at a section associated with a larger optical mode.

Abstract: Scribing operations with reduced substrate heating can be provided by applying multiple optical pulses to a substrate within a time interval that is less than a material recombination time. Typically a series of pulses of durations of 5-200 ps with pulse energies of less than about 0.002 mJ can be applied at rates of about 1 MHz to about 30 MHz. Beam area and beam scanning are configured to provide substantial overlap so that material can be removed by cold ablation.

Abstract: A stable, single mode fiber amplifier is described. The amplifier consists of a seed source, a passive single clad multimode fiber, an active double clad multimode fiber or a multimode fiber horn and a semiconductor laser pump source. The passive fiber is packaged on a mandrel with a compound radius of curvature such that high order modes in the fiber are stripped from the core leaving only the fundamental mode. This fiber is then spliced to a multimode active fiber of similar core diameter. By exciting only the fundamental mode of this active fiber, stable single mode amplification is achieved.

Abstract: An exposure apparatus for skin treatment or other applications includes a laser diode module controller that is configured to operate one or more laser diodes that are situated to provide optical radiation to an exposure aperture. A two-dimensional position sensor is secured to the exposure aperture and provides an exposure aperture translation signal that is coupled to the laser diode module controller. Delivery of optical radiation to the exposure aperture by the laser diode module controller is based on an exposure aperture translation or velocity that is estimated based on the exposure aperture translation signal. In addition, a clock or timer is coupled to the laser diode module controller to permit selection of laser diode pulse duty cycle or to provide safe or comfortable skin treatment. The two dimensional position sensor can be based on optical sensing such as provided in an optical mouse, and can also provide proximity sensing for safe, efficient operation.

Abstract: An optic device is placed in close proximity to multiple gain elements so as to selectively modify the divergence of the light from said multiple elements such that when the light is subsequently collimated and diffracted from a grating and focused into an optical fiber, it will have a predefined cross-section that matches the mode of the fiber. Using this system and method, a more efficient light transfer is achieved in an intracavity fiber coupled multigain element laser.

Abstract: The present invention is directed to a system and method which provide a Raman pump which is spectrally tailored in response to feedback from control structure associated with the Raman pump source. In certain embodiments of the present inventions, an incoherently beam combined laser (IBC) is utilized to provide a spectrally tailored Raman pump. In these embodiments, emitters in an emitter array are either individually addressable or block addressable to facilitate adjustment of emitter output power. By adjustment of the output power, the Raman pump may be spectrally tailored. The spectral tailoring can occur by employing suitable control algorithms to algorithms to dynamically maintain reasonably flat Raman gain.

Abstract: The present invention is directed to a system and method for providing a spectrally tailored Raman pump. The system and method employ an incoherently beam combined laser configuration to combine output beams from a plurality of emitters. Embodiments of the present invention provide emitter devices with electrodes adapted to allow addressability of various emitters. In some embodiments, each emitter is individually addressable thereby allowing the output power of each emitter to be controlled by a drive current. In another embodiment, blocks of emitters are coupled to a single current source. Each emitter of a block is operated at a common power level. In certain embodiments, blocks of emitters are driven at current levels significantly greater than the threshold current for the emitters to increase operating efficiency. Moreover, certain embodiments vary emitter spacing to increase linear power density and/or to allocate additional power to the blue end of the Raman pump.

Abstract: A wide variety of Fiber Bragg writing devices comprising solid state lasers are provided. The solid state lasers emit moderate peak-power output beams which are suitable for efficient production of fiber Bragg gratings without causing embrittlement of the optical waveguide. These solid state lasers generate fourth harmonic output beams with wavelengths of approximately 240 nm, in order to match the primary absorption peak in the ultraviolet range for a typical optical waveguide. Some of these solid state lasers comprise a fequency-doubling crystal and a CLBO crystal used in a non-critically phase-matched orientation as a frequency-quadrupling crystal. In such lasers, both the frequency-doubling crystal and frequency-quadrupling crystal are preferably engineered to minimize or eliminate beam “walkoff.