Ipg Photonics Corporation

Mikhail Vyatkin

Valentin Gapontsev

Ilia Zaytsev

Vladimir Grigoriev

Dan Myasnikov

Ilya Zaytsev

Vladimir Sergueev

A fiber block is configured with a fiber block including a Nd-doped active fiber and a pump-light delivery fiber which has a stretch extending along the active fiber in a side-to-side configuration so as to lunch pump light into the Nd-doped core of the active fiber. The core of the active fiber is surrounded by at least one or more claddings which, like the core, have a double bottleneck cross-section with a relatively large-area central region and relatively small input and output regions. The pump light delivery fiber is structured to have a substantially dumbbell cross-section with a relatively small-area central region coextending with the central region of the active fibers. The active fiber is dimensioned so that the overall length of the active fiber is configured to provide for the maximal amplification of the laser signal in a 900 nm range while limiting amplification in the 1060 nm range to the preset threshold. The fiber block is further configured so as to have the major fraction of the unabsorbed light, supported in the relatively large-area output end region of the passive fiber, be further used for pumping a neighboring fiber block.

High power neodymium fiber lasers and amplifiers

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.

Fiber with asymmetrical core and method for manufacturing same

A large mode area optical fiber includes a large diameter core (dup to 60 &#x3bc;m), and a first cladding (diameter d) wherein the difference between refractive index (n) in the core and the first cladding (n) is very small (&#x394;n&#x3c;0.002), thus providing a very low numerical aperture core (NAbetween 0.02 and 0.06). The preferred ratio of d/d&#x3c;2. The fiber further has a second cladding, preferably a layer of air holes, having a very low refractive index nas compared to the core and first cladding such that the first cladding has a relatively high numerical aperture (NA&#x3e;0.4) (nis preferably less than 1.3). The small change in refractive index between the core and inner cladding combined with a large change in refractive index between the first cladding and second cladding provides a significantly improved single mode holding waveguide.

Growing community of inventors

Fryazino, Russia

Mikhail Vyatkin