Ipg Photonics Corporation

Vladimir Grigoriev

Valentin Gapontsev

Volodia Sergueev

Mikhail Vyatkin

Ilia Zaytsev

A twin fiber laser arrangement is configured with active and passive fibers supporting respective signal and pump lights and a reflective coating surrounding the fibers along a section of the arrangement. The passive fiber has regions covered by respective protective layer and coating-free regions alternating with the layer covered regions, wherein the reflective coating is configured to overlap the protective layer which shields the end of the reflective coating from high power pump light.

High power fiber laser system with side-pumping arrangement

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

Burbach, Germany

Vladimir Grigoriev