Abstract: The disclosed ultra-high power all fiber laser system is configured with multiple spaced apart fiber lasers outputting respective laser beams respective paths, The disclosed system is further configured with a tapered fiber-bundle including at least one central guiding fiber and a plurality of peripheral guiding fibers. The disclosed system further has a multiclad, delivery fiber configured with a double-bottle neck cross-section and provided with at least two concentric and radially spaced apart inner and outer cores. The inner core is coupled to the peripheral guiding fibers while the inner core is spliced to the central guiding fiber so that a system output emitted from the inner core of the delivery fiber has a different beam shape from the system output emitted from the outer core.

Abstract: An active waveguide including active and passive rods which have respective polymeric claddings mechanically and optically coupled to one another so as to define a side pumping scheme. One or a plurality of elements are embedded in one of or both active and passive rods and have a refractive index lower than the lowest of refractive indices of the respective active and passive rods at least 1*10?3. The MM core of the active rod includes inner and outer concentric regions with a concentration of light emitters in the outer region being lower than that of the inner region at more than 50% and, a radius of the inner region being at most 92% of that of the outer region. The unabsorbed pump light at the output of the active waveguide constitutes less than 1% of the delivered pump light which in combination with the refractive index of the embedded elements and selectively doped core regions contribute to laser efficiency of at least 86%.

Abstract: A method of inducing light losses at a parasitic wavelength in a fiber laser system includes providing a wavelength discriminator (WD) spaced from and between feeding and process fibers or from the end output of the feeding fiber so as to induce losses of light at parasitic wavelength. The device implementing the disclosed method is configured with a laser source, the delivery fiber and WD spaced at a distance between the surface to be treated and the end of the delivery fiber, wherein the WD receives the parasitic light over free space and is configured as a dichroic filter inducing losses to the light at the parasitic wavelength.

Abstract: A method of inducing light losses at a parasitic wavelength in a fiber laser system includes providing a wavelength discriminator (WD) spaced from and between feeding and process fibers or from the end output of the feeding fiber so as to induce losses of light at parasitic wavelength. The device implementing the disclosed method is configured with a laser source, the delivery fiber and WD spaced at a distance between the surface to be treated and the end of the delivery fiber, wherein the WD receives the parasitic light over free space and is configured as a dichroic filter inducing losses to the light at the parasitic wavelength.

Abstract: A single mode (SM) high power laser system is configured with a laser source outputting a single mode or low mode kW-power light and a passive delivery fiber spliced to an output fiber of the fiber laser source and having a double bottleneck-shaped core. The latter is configured to increase a threshold for nonlinear effects in general and in particular for stimulated Raman scattering (SRS) so that the delivery passive fiber has a fiber length at least twice the length of a delivery passive fiber with a standard uniformly dimensioned core, which may be used with the same laser source, while outputting the kW-power light with an M2 factor less than 2.

Abstract: The present invention provides a multi-fiber laser output system that delivers at least three fiber outputs arranged in a circumferential pattern or otherwise at least four distinct laser outputs from a single processing cable. The present invention allows for controlling the at least three laser modules and delivering their respective outputs in a pre-determined sequence in a single processing cable, thereby providing multiple processing steps on a work piece that heretofore required separate optics for each beam. The at least three laser outputs are optimized for use in creating spot welds, seam welds or virtual wobble welds when used for seam welding.

Abstract: The present invention provides a fiber laser system that delivers from a single processing cable a multibeam output. The present invention allows for controlling multiple fiber laser modules and delivering their respective outputs in a pre-determined sequence but in a single processing cable, thereby providing multiple processing steps on a work piece that heretofore required separate optics for each beam. Custom fiber laser systems that combine processing steps tailored for a specific industrial application such as pre-heating, cutting, cleaning, welding, brazing, ablating, annealing, cooling, polishing and the like can be readily provided because of the present invention.

Abstract: The inventive laser is configured with a plurality of pigtailed multimode (MM) diode lasers each receiving a direct input current at a room temperature which is maintained to be within a 20-25° C. inside the housing of the laser. The diode lasers each are configured to operate at a desired wavelength in an optimal operational range, in which the diode laser operates with a WPE range between 63% and 75%. The direct current inputted in each diode laser is selected to be below a threshold at an efficiency curve of the diode laser after which the efficiency of the diode laser starts decreasing while an output power of the diode laser continues to increase. The laser is further configured with a fiber gain block having an active fiber medium which is pumped with the cumulative pump output and operative to emit a laser output in a power range between hundreds of watts and tens and even hundreds of kilowatts at the desired wavelength in an optimal operation range.

Abstract: A method of inducing light losses at a parasitic wavelength in a fiber laser system includes providing a wavelength discriminator (WD) spaced from and between feeding and process fibers or from the end output of the feeding fiber so as to induce losses of light at parasitic wavelength. The device implementing the disclosed method is configured with a laser source, the delivery fiber and WD spaced at a distance between the surface to be treated and the end of the delivery fiber, wherein the WD receives the parasitic light over free space and is configured as a dichroic filter inducing losses to the light at the parasitic wavelength.

Abstract: The inventive laser is configured with a plurality of pigtailed multimode (MM) diode lasers each receiving a direct input current at a room temperature which is maintained to be within a 20-25° C. inside the housing of the laser. The diode lasers each are configured to operate at a desired wavelength in an optimal operational range, in which the diode laser operates with a WPE range between 63% and 75%. The direct current inputted in each diode laser is selected to be below a threshold at an efficiency curve of the diode laser after which the efficiency of the diode laser starts decreasing while an output power of the diode laser continues to increase. The laser is further configured with a fiber gain block having an active fiber medium which is pumped with the cumulative pump output and operative to emit a laser output in a power range between hundreds of watts and tens and even hundreds of kilowatts at the desired wavelength in an optimal operation range.

Abstract: A hand displaceable laser welding gun is configured with an elongated support column extending along a longitudinal axis and made from lightweight material. A support plate is displaceably mounted to the column while supporting thereon an optical head axially which is provided with optics. The optics is configured to direct a laser beam along a path towards a welding zone through a protective window of the optical head. The laser welding gun further is structured with a first arm mounted to the support plate and extending along a longitudinal axis of the gun diametrically opposite to the optical head. The inner surface of the displaceable arm has an inner surface defining a tunnel which is aligned with the optical head and axially traversed by the laser beam, a first axially flowing stream of pressurized gaseous medium, and a second axially flowing stream of gaseous medium.

Abstract: The present invention provides a fiber laser system that delivers from a single processing cable a multibeam output. The present invention allows for controlling multiple fiber laser modules and delivering their respective outputs in a pre-determined sequence but in a single processing cable, thereby providing multiple processing steps on a work piece that heretofore required separate optics for each beam. Custom fiber laser systems that combine processing steps tailored for a specific industrial application such as pre-heating, cutting, cleaning, welding, brazing, ablating, annealing, cooling, polishing and the like can be readily provided because of the present invention.

Abstract: A single mode (SM) high power laser system is configured with a laser source outputting a single mode or low mode kW-power light and a passive delivery fiber spliced to an output fiber of the fiber laser source and having a double bottleneck-shaped core. The latter is configured to increase a threshold for nonlinear effects in general and in particular for stimulated Raman scattering (SRS) so that the delivery passive fiber has a fiber length at least twice the length of a delivery passive fiber with a standard uniformly dimensioned core, which may be used with the same laser source, while outputting the kW-power light with an M2 factor less than 2.

Abstract: The present invention provides a multi-fiber laser output system that delivers at least three fiber outputs arranged in a circumferential pattern or otherwise at least four distinct laser outputs from a single processing cable. The present invention allows for controlling the at least three laser modules and delivering their respective outputs in a pre-determined sequence in a single processing cable, thereby providing multiple processing steps on a work piece that heretofore required separate optics for each beam. The at least three laser outputs are optimized for use in creating spot welds, seam welds or virtual wobble welds when used for seam welding.

Abstract: A high power fiber laser system includes a booster winch is configured as a fiber amplifier extending over free space, pump source and laser head including a reflective element which receives pump light and reflects toward the output end of the booster in a counter signal-propagating direction. The booster is configured with concentric and coextending frustoconically shaped (“MM”) core and cladding around the core. The core includes a mode transition region expanding between small diameter SM input and large diameter MM output core ends and configured so that amplification of high order modes is substantially suppressed as a single mode (“SM”) signal light propagates from the input to output core ends. The laser head receives output ends of respective pump light delivery fibers and signal fiber, respectively. The pump source is structured with a plurality of independent sub pumps arranged around the booster.

Abstract: A clad absorber unit is provided on a passive fiber of a high power fiber laser system and operative to trap and remove high order modes propagating along the clad of the passive fiber. The mode absorber has a composition made from one or more liquid metals and alloys thereof which are placed in the opening formed in the sheath of the passive fiber. The composition is configured to remove from the cladding the MM light having a predetermined light power which heats the composition at a temperature lower than a threshold temperature at which the absorber may be damaged.

Abstract: A clad absorber unit is provided on a passive fiber of a high power fiber laser system and operative to trap and remove high order modes propagating along the clad of the passive fiber. The mode absorber has a composition made from one or more liquid metals and alloys thereof which are placed in the opening formed in the sheath of the passive fiber. The composition is configured to remove from the cladding the MM light having a predetermined light power which heats the composition at a temperature lower than a threshold temperature at which the absorber may be damaged.

Abstract: A high power fiber laser system is configured with a combiner end fiber spliced to a combiner output fiber. The system further includes a light stripper extending along the combiner end and output fibers and configured with sequentially located zones which are provided with respective refractive indices. In a forward propagating direction of light signal, the upstream zone includes polymeric material with the refractive index higher than that of the cladding of the combiner end fiber. This zone is configured to remove the backreflected core guided light bled into the cladding of the combiner through a splice between combiner end and output fibers. The intermediate zone includes polymeric material configured with a refractive index lower than that of the cladding of the combiner output fiber so it can prevent clad guided signal light from decoupling the cladding under the material.

Abstract: A hand displaceable laser welding gun is configured with an elongated support column extending along a longitudinal axis and made from lightweight material. A support plate is displaceably mounted to the column while supporting thereon an optical head axially which is provided with optics. The optics is configured to direct a laser beam along a path towards a welding zone through a protective window of the optical head. The laser welding gun further is structured with a first arm mounted to the support plate and extending along a longitudinal axis of the gun diametrically opposite to the optical head. The inner surface of the displaceable arm has an inner surface defining a tunnel which is aligned with the optical head and axially traversed by the laser beam, a first axially flowing stream of pressurized gaseous medium, and a second axially flowing stream of gaseous medium.

Abstract: A fiber connector system provides a pigtailed monolithic terminal block of a fiber connector configured to alter a space distribution of laser output radiation. The output facet of the pigtailed monolithic terminal block is configured to alter the divergence of an output beam allowing collimation, focusing, or any desired distribution without additional optical circuitry. The fiber connector system is operative to couple two fibers from respective different fiber devices and allows positioning additional optical components there between.