Open AccessWavelength resolved intracavity measurement of the cross sections of a Tm-doped fiber
Author(s) -
Martin Engelbrecht,
Frithjof Haxsen,
Dieter Wandt,
Dietmar Kracht
Publication year - 2008
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.16.001610
Subject(s) - laser linewidth , materials science , optics , fiber laser , laser , slope efficiency , thulium , wavelength , optoelectronics , doping , physics
The wavelength dependent measurement of the relaxation oscillation frequency in a laser oscillator allows the study of the three- and four-level nature of the active material. Accordingly we present a tunable thulium doped fiber laser that covers the transition from three- to four-level operation at 2025 nm, characterized by the vanishing occupation of the terminal laser level. The laser is tunable from 1864 nm to 2075 nm with a linewidth below 0.3 nm. A maximum output power of 3.8 W at 1930 nm was achieved with a slope efficiency of 33.6% and an absorbed pump power of 17.5 W. Absorption and emission cross sections were derived over the tuning range by an intracavity measurement method.