Ipg Photonics Corporation

Other

Nikolai Platonov

Valentin Gapontsev

Valentin Fomin

Roman Yagodkin

Volodia Sergueev

Mikhall Vyatkin

Michael Vyatkin

A monolithic fiber has a double bottleneck-shaped core configured with opposite uniformly configured end regions, frustoconical transformer regions which run inwards from the respective end regions, and a central uniformly-dimensioned region which bridges the transformer regions. The core is configured as a multimode core or single-mode core and capable of guiding a single transverse mode between the end regions without splice losses.

Single mode high power fiber laser system

A high power single mode fiber laser system has a monolithic active fiber configured with a double bottleneck-shaped multimode (MM) core which is capable of supporting substantially only a fundamental mode at a given wavelength. The core has opposite uniformly configured end regions, frustoconical transformer regions running inwards from the respective end regions, and a central uniformly-dimensioned region which bridges the transformer regions. The MM core is configured with a refractive step-index profile which includes a continuous dip configured to shape an intensity field of the fundamental mode from a Gaussian or dome-shaped field profile to a two-peak-shaped profile and back to the Gaussian filed profile.

Optical fiber apparatus having a wavelength of operation, that comprises an optical fiber including a core comprising an active material for providing light having the operating wavelength responsive to the optical apparatus receiving pump optical energy having a pump wavelength; a cladding disposed about the core; at least one region spaced from the core; and wherein the optical fiber is configured and arranged such that at the wavelength of operation the optical fiber can propagate a plurality of modes and wherein the optical fiber comprises a fundamental mode that is primarily a mode of the core and at least one higher order mode (HOM) that is a mixed mode of a selected mode of the core and of a selected mode of the at least one region.

Optical fiber apparatus with suppression of higher order modes

Optical apparatus, comprising an optical fiber having a wavelength of operation, the optical fiber comprising an inner core, the inner core supporting a fundamental mode and at least first and second higher order modes (HOMs) at the wavelength of operation; a first ring-shaped core region spaced from and disposed about the inner core; a second ring-shaped core region spaced from and disposed about the ring-shaped core region; and wherein the optical fiber is configured and arranged such that the first HOM optically interacts with the first ring-shaped core region and the second HOM optically interacts with the second ring-shaped core region.

Optical fiber with multiple ring-shaped core regions

An optical fiber apparatus having a wavelength of operation comprises an optical fiber comprising a core; a pump cladding disposed about the core for receiving pump optical energy having a pump wavelength; and a second cladding disposed about for tending to confine pump optical energy to the pump cladding. The core can comprise a rare earth material for providing optical energy having the wavelength of operation responsive to the optical fiber receiving the pump optical energy, and the fiber can further comprise at least one ring core spaced from the core, the ring core defined by inner and outer diameters and comprising the cross sectional area therebetween. The ring core can comprise an absorbing material for absorbing optical energy having the wavelength of operation. At the wavelength of operation the optical fiber can comprise a fundamental mode that is primarily a mode of the core and at least one higher order mode (HOM) that is a mixed mode of a selected mode of the core and of a selected mode of the ring core, the selected modes being of the same azimuthal order. The mixed mode can be suppressed relative to the fundamental mode.

Double clad optical fiber having ring core surrounding core for high power operation

A high power single mode fiber laser system is configured with an active fiber including coextending multimode core (MM) and cladding around the MM core. The MM core is doped with one or more ions selected from rare earth and transitional metals and has a bottleneck cross in accordance with one aspect of the disclosure. The bottleneck cross-section includes a relatively small uniformly dimensioned input end region, a frustoconical region and a relatively large uniformly dimensioned amplifying region. The refractive step index of the MM core is configured with a central dip shaped and dimensioned along the input region so as not to disturb a Gaussian field profile of fundamental mode, gradually transform the Gaussian field profile into the ring profile of the fundamental mode and support the latter along the amplifying region. In accordance with a further aspect, the core is further provided with an output transforming region with the dip which gradually shapes the ring field profile in the Gaussian field profile further distortlessly supported by the output end region. A variety of end and side pumping arrangements are employed with the structures configured in accordance with the first and second aspects.

Single-mode high power multimode fiber laser system

A monolithic fiber is configured with a double bottleneck-shaped multimode (MM) core capable of supporting substantially only a fundamental mode at a given wavelength and having opposite end regions, frustoconically shaped transformer regions, which run inwards from the respective end regions, and a central uniformly dimensioned region, which bridges the transformer regions. The MM core has a refractive step-index profile which is configured with a centrally positioned dip having a variable width along the length of the fiber. The width of the dip is relatively small at the end regions of the MM core so as to support only the fundamental mode with a Gaussian profile. As the dip becomes larger along the input transformer region, it gradually shapes the Gaussian profile into the ring profile of the fundamental mode, which is guided along the central region of the MM core. The dip gradually becomes smaller along the output transition region so as to shape the ring profile back into the substantially Gaussian profile of the fundamental mode radiated from the output end region of the MM core. The refractive index profile has a ring area doped with one or more rare-earth elements and configured to amplify substantially only the fundamental mode.

Single-mode high-power fiber laser system

A powerful fiber laser system is configured with at least one large-area multi-clad rare-earth doped fiber, which is configured with a MM core capable of propagating a single mode laser emission at a first wavelength, and with at least one pumping assembly capable of generating an optical pump output at a wavelength shorter than the first wavelength of the rare-earth doped fiber. The pumping assembly has a plurality SM fiber lasers coupled to a SM-MM combiner which is operative to lunch the pump output into the cladding of the rare-earth doped fiber so that the powerful fiber laser system is operative to deliver a power of up to 20 kW.

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Worcester, MA, United States of America

Nikolai Platonov