Abstract: An ultra-high power fiber laser system includes a multimode combiner which is configured with a plurality of low mode fibers bundled together and tapering toward its downstream end. A clad mode absorber extends along the tapered downstream end and over a portion of the combiner's output fiber. The absorber is configured with adjacent zones which are provided with respective refractive indices. In a forward propagating direction of signal, the upstream zone includes polymeric material with the refractive index higher than that of the cladding of the combiner end fiber. The intermediate zone includes polymeric material configured with a refractive index lower than that of the cladding of the combiner output fiber. The downstream zone is configured with polymeric material having a refractive index lower than that of the cladding of the combiner output fiber and impregnated with a plurality of light diffusers.

Abstract: An improved high power spatial filter, system and method. In the system, an optical fiber is disposed inside a ferrule channel structure, and the channel structure is aligned with a focusing lens system. The end of the fiber is at a distance D from the channel opening that faces the focusing lens system, and D is determined by the system's numeric aperture factor and the cladding thickness of the optical fiber.

Abstract: A laser illuminated projector system is configured with multiple Red, Green and Blue laser sources. The Green laser source has an all fiber master oscillator power amplifier configuration in which pump light is coupled into the output end of the fiber amplifier in a counter-propagation direction rendering the structure of the Green source and therefore projector system compact. The Green laser source is operative to emit signal light pulses at about 1064 nm wavelength with a pulse repetition reaching of up to about 3000 kHz, pulse duration between about a 100 fm to about 100 psec, an average power between 1.5 W to above 30 W, a peak power above 5 MW, a pulse energy exceeding 100 ?J and a beam quality parameter M2 ranging between 1.2 and 1.5. The thus configured Green laser source substantially reduces speckle otherwise visible on the laser illuminated screen.

Abstract: A high power pump ultra bright low-noise source is configured with a multimode (“MM”) seed source outputting a MM smooth, low-noise signal light at a wavelength ?p in a wavelength range between about 900 and 940 nm, a MM Yb fiber wavelength converter operative to convert emission of a plurality of high power (“HP”) semiconductor laser diodes at a wavelength ?sp to a pump output at the desired wavelength ?p. The Yb-doped MM wavelength converter is configured with noise levels substantially identical to and lower than those of the low-noise signal light, brightness (“B”) substantially equal to n×B, wherein n is a number HP semiconductor laser diodes, and B is brightness of each HP laser diode, and output power (“Po”) substantially equal to nPd, wherein Pd is a power of each HP laser diode, and n is the number thereof.

Abstract: A high power fiber laser system consisting of multiple fiber amplifier or laser systems amplifying the input signal in parallel is configured with a high power splitter such as to share some of the gain stages. The high power splitting component consists of high power fiber couplers and splitter(s). The splitter is a holographic optical element, a dielectric coated plate, a diffraction grating, or a volume Bragg grating. The resultant fiber laser configuration reduces the total number of amplifying stages including optical isolators and active fiber assemblies for the system and thus reduces the total volume and weight.

Abstract: A high power fiber laser system emitting a substantially diffraction limited beam with a Gaussian intensity profile includes a single mode (“SM”) neodymium fiber pump source outputting a SM pump light; a seed laser operative to emit a SM signal light at a wavelength greater than that of the pump light; a SM DWM receiving and multiplexing the SM pump and signal lights. The disclosed system further includes a booster fiber amplifier which is configured with a frustoconically-shaped ytterbium (“Yb”) doped core receiving the pump and signal lights and configured with a small diameter input end which supports only a SM and a large diameter output end which is capable of supporting the SM and high order modes (:HOM”). The booster further has a cladding surrounding and coextending with the core, the core being configured for having intensity profiles of respective SMs of pump and signal lights overlap one another so that an overlap integral substantially equals to one (1) along an entire length of the core.

Abstract: A method for sum-frequency conversion of coherent radiation includes generating two linearly polarized waves at different first f1 and second f2 frequencies (f2>f1), respectively, which coaxially propagate and are characterized in common case by arbitrarily located polarization planes. The waves are further guided through an optical active crystal which rotates their polarization planes at different angles ?1 and ?2 determined as ?1=?(f1)·L and ?2=?(f2)·L, where L is a length of the optical active crystal, and ?(f1) and ?(f2) specific rotations at respective frequencies f1 and f2. Finally the waves with the rotated polarization planes are incident on a non-linear crystal configured to generate a third frequency.

Abstract: An optical active fiber is configured with an asymmetrically-shaped core having at least one long axis and a shortest axis which extends transversely to the long axis. The outmost cladding of the active fiber is configured with a marking indicating the orientation of the short axis. The marking allows for bending the fiber so that the shortest axis extends along and lies in the plane of the bend thereby minimizing distortion of a mode which is guided by the asymmetrically-shaped core as light propagates along the bend.

Abstract: A module is configured with a housing enclosing a diode laser. Fast and slow axes collimators are located behind the rear facet of the laser, which along with a front facet, defines an intra-cavity cavity of the laser. The facets are partially transmissive to light and therefore emit laser light. A wavelength selective optical element is aligned with the collimators and configured to reflect light emitted through the back facet and processed by collimators back into the intra-cavity. As a result, the laser beam is emitted through the front facet at a wavelength locked on the desired wavelength of the optical element. A delivery fiber is mechanically coupled to the front facet of diode laser and configured to receive and guide the emitted laser beam along the path of light.

Abstract: A single frequency laser system is configured with an elongated housing extending along a longitudinal axis and having opposite axially spaced upstream and downstream ends. The housing encloses a laser chip configured to emit a radiation which propagates along a light path and emitted through the downstream faucet thereof. One or more spaced frequency discriminators are mounted in the housing downstream from the chip so as to define an external resonant cavity with the upstream faucet of the of the laser chip. At least two or more separate thermoelectric coolers (“TEC”) are mounted in the housing to control the chip arid discriminators so that the system emits radiation at the desired frequency.

Abstract: A pulsed laser system may include a Raman fiber that is configured to act as multiple wavelength Raman laser. The fiber is configured to receive a pulsed input beam from an input source and convert the input beam to an output beam having narrow band outputs at first and second frequencies v1 and v2.

Abstract: Laser lift off systems and methods may be used to provide monolithic laser lift off with minimal cracking by reducing the size of one or more beam spots in one or more dimensions to reduce plume pressure while maintaining sufficient energy to provide separation. By irradiating irradiation zones with various shapes and in various patterns, the laser lift off systems and methods use laser energy more efficiently, reduce cracking when separating layers, and improve productivity. Some laser lift off systems and methods described herein separate layers of material by irradiating non-contiguous irradiation zones with laser lift off zones (LOZs) that extend beyond the irradiation zones. Other laser lift off systems and methods described herein separate layers of material by shaping the irradiation zones and by controlling the overlap of the irradiation zones in a way that avoids uneven exposure of the workpiece.

Abstract: A high power fiber laser system consisting of multiple fiber amplifier or laser systems amplifying the input signal in parallel is configured with a high power splitter such as to share some of the gain stages. The high power splitting component consists of high power fiber couplers and splitter(s). The splitter is a holographic optical element, a dielectric coated plate, a diffraction grating, or a volume Bragg grating. The resultant fiber laser configuration reduces the total number of amplifying stages including optical isolators and active fiber assemblies for the system and thus reduces the total volume and weight.

Abstract: A method and apparatus are operative to control the desired level of population inversion in a gain medium having an amplified spontaneous emission (ASE) spectrum which is characterized by distinct short- and long-wavelength regions. The control is realized by the apparatus configured to determine a relationship between the regions of the ASE spectrum represented by respective frequencies which are filtered by respective frequency discriminators. The apparatus includes a controller operative to process the filtered frequencies by determining a relationship between amplitudes of the respective filtered frequencies which represents a measured level of population inversion. Upon mismatch between the measured level and desired level of the population inversion, a control signal is coupled into a pulse generator or pump or both. In response, the pulse generator may output a pulse, or/and the pump may be completely shut down to lower the level of the measured inversion.

Abstract: A clad absorber unit is provided on a passive fiber of a high power fiber laser system and operative to trap and remove modes propagating along the waveguide clad of the fiber. The mode absorber is configured with such an optimal length that the clad light may be removed in a localized manner, substantially uniformly removed over the entire length thereof. The absorber removing clad light in a unformed fashion includes a host material impregnated with diffusers.

Abstract: A beam coupler alignment system for a fiber laser system is disclosed. The system includes a focus adjust collimator assembly having an inner and outer housing assembly portion. The inner assembly includes a coupler housing assembly and a modified lens housing received within and adjustable relative to via a mechanism configured and arranged to apply an asymmetric binding force in a predictable and repeatable manner. A lever assembly contacts the lens housing and exerts an off-center (asymmetric) force relative to coupler housing assembly creating a friction bind eliminating X and Y axis movement yet allowing Z axis movement with minimal effort. The assembly may further include an alignment mechanism configured and arranged to optically align an input collimator unit and an output collimator unit of a complex fiber laser system about a common optical axis using the proposed assembly.

Abstract: An improved high power special filter, system and method. In the system, an optical fiber is disposed inside a ferule channel structure, and the channel structure is aligned with a focusing lens system. The end of the fiber is at a distance D from the channel opening that faces the focusing lens system, and D is determined by the system's numeric aperture factor and the cladding thickness of the optical fiber.

Abstract: A method for manufacturing submounts for laser diodes includes the steps of providing a base configured with a ceramic carrier and a metal layer deposited upon the substrate. The method further includes using a pulsed laser operative to generate a plurality of pulses which are selectively trained at predetermined pattern on the metal layer's surface so as to ablate the desired regions of the metal layer to the desired depth. Thereafter the base is divided into a plurality of submounts each supporting a laser diode. The metal layer includes a silver sub-layer deposited upon the ceramic and having a thickness sufficient to effectively facilitate heat dissipation.

Abstract: The disclosure is a method and system for monitoring the condition of an optical protective component in a laser system associated with a data processor. In one embodiment, the method begins with directing light from the process head of a laser through the optical protective component onto a workpiece. A return light via the workpiece causes light signals coupled through the protective component and into to a fiber which extends proximate the protective component and thereafter flexibly to a sensor. The sensed signals allow monitoring the condition of the protective component during use. The method and system is operative for use with optical protective elements downstream of the process head.

Abstract: The present invention relates to a dynamic height adjusting system and method that uses capacitance for a head assembly of a laser processing system throughout a process cycle. The proposed system and method involves use of a single frequency in which a change in phase is measured and processed to determine changes in height and distance between a work piece with an increased reliability. The system further enables operative computerized processor control and substantial improvements in process control signal and feedback distribution throughout an integrated system and optional remote interfaces.