Spatial beam self-cleaning in tapered Yb-doped GRIN multimode fiber with decelerating nonlinearity
01 Pubblicazione su rivista
Niang Alioune, Levchenko Andrey E., Semjonov Sergei L., Lipatov Denis S., Babin Sergey, Couderc Vincent, Wabnitz Stefan, Modotto Daniele, Tonello Alessandro, Mangini Fabio, Minoni Umberto, Zitelli Mario, Fabert Marc, Jima Mesay Addisu, Egorova O. N.
ISSN: 1943-0655
We experimentally demonstrate spatial beam self-cleaning in an Yb-doped graded-index multimode fiber taper, both in passive and active configurations. The input laser beam at 1064 nm was injected for propagation from the small to the large core side of the taper, with laser diode pumping in a counterdirectional configuration. The Kerr effect permits to obtain high-beam quality amplification with no accompanying frequency conversions. As a result, our nonlinear taper amplifier may provide an important building block for multimode fiber lasers and amplifiers.