High-power 2.3 µm Tm:YLF laser with intracavity upconversion pumping by a Nd:ASL laser at 1051 nm.

A Tm:LiYF laser operating on the H→ H transition is embedded in a high-power diode-pumped Nd:ASL laser for intracavity upconversion pumping at 1.05 µm. This leads to a record-high output power at 2.

Cascade laser optimization for H → H and F → H sequent transitions in Tm-doped materials.

We study a cascade laser scheme involving the H → H and F → H consecutive transitions in Tm-doped materials as a promising technique to favor laser emission at 2.3 µm. We examine the conditions in terms of the Tm doping levels for which the cascade laser is beneficial or not.

Tm:CALGO lasers at 2.32 µm: cascade lasing and upconversion pumping.

We report on the first laser operation of a disordered Tm:CaGdAlO crystal on the H → H transition. Under direct pumping at 0.79 µm, it generates 264 mW at 2.

Excited-state absorption and upconversion pumping of Tm-doped potassium lutetium double tungstate.

We report on a bulk thulium laser operating on the H → H transition with pure upconversion pumping at 1064 nm by an ytterbium fiber laser (addressing the F → F excited-state absorption (ESA) transition of Tm ions) generating 433 mW at 2291 nm with a slope efficiency of 7.4% / 33.2% vs.

Dual-wavelength-pumping of mid-infrared Tm:YLF laser at 2.3 µm: demonstration of pump seeding and recycling processes.

Upconversion pumping of thulium lasers emitting around 2.3 µm (the H → H transition) has recently attracted a lot of attention as it is compatible with the mature Yb-laser technology. To explore this possibility, we built a mid-infrared Tm:LiYF laser pumped by an Yb:CaF laser at 1.