High power fiber laser system with distributive mode absorber
AssigneeIpg Photonics Corporation
InventorsValentin Gapontsev, Valentin Fomin, Mikhail Abramov, Anton Ferin
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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.
Claims29
A clad mode stripper (“CMS”) unit for a high power fiber laser system, comprising:
- a passive fiber configured with a core, at least one waveguide cladding surrounding the core, and a polymeric sheath coated upon the cladding and having a discontinuous surface which defines an opening terminating in a plane of the cladding;
- and
- a clad mode stripper (“CMS”) filling the opening so as to cover an exposed portion of the cladding, the CMS being configured to provide a substantially uniform removal of a multimode (“MM”) light from the cladding along an entire length of the CMS at a maximum dissipated light power heating the CMS at a temperature lower than a thermal threshold at which the CMS is damaged.
A method of manufacturing a clad mode absorber unit for a fiber laser system having a plurality of passive fibers each of which is configured with a core, at least one cladding surrounding the core and capable of guiding an undesired multimode (“MM”) light, and a polymeric sheath upon the cladding;
- the method comprising:
- removing a portion of the sheath at a desired location, thereby forming an opening in the sheath so as to expose a length of the cladding;
- and
- configuring a clad mode stripper (“CMS”) with an optimal length dimensioned so that, upon being applied to the cladding within the opening, the CMS is operative to substantially uniformly remove the MM along the optimal length thereof at a maximum dissipated light power lower than a thermal threshold at which the CMS is damaged.
A high power fiber laser system, comprising:
- at least one gain block operative to emit a high power radiation;
- a plurality of passive fibers optically coupled to the gain block, the passive fiber each having a core, at least one cladding surrounding the core and configured to guide multimode (“MM”) light, and a sheath upon the cladding, at least one of the passive fibers having a part of the sheath removed so as to expose the cladding;
- a clad mode stripper (“CMS”) applied to the exposed cladding and configured to provide a substantially uniform removal of the MM light from the cladding along an entire length of the CMS at a maximum dissipated light power heating the CMS at a temperature lower than a thermal threshold at which the CMS is damaged.
Dependencies are inferred from the claim text.