Abstract

Femtosecond mode-locked lasers near 2 μm based on the Tm³⁺ ion have been drawing great attention since they are applied in various fields including physics, chemistry and biology [1]. Among the host materials for Tm³⁺, the monoclinic double tungstate crystals are one of the most promising for ultrashort pulse generation [2]. Recently, we successfully demonstrated efficient laser operation of a new monoclinic divalent metal monotungstate, Tm³⁺:MgWO₄, crystal [3]. Due to the low-symmetry structure and the distortion of the rare-earth site caused by the mismatch of the ionic radii of Mg²⁺ and Tm³⁺, the absorption and emission bands of Tm:MgWO₄ are rather broad. Motivated by these attractive spectroscopic properties, we study here mode-locked laser operation of Tm:MgWO₄ using a single-walled carbon nanotube (SWCNT) based saturable absorber (SA) in the present work.

© 2017 IEEE