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.

Excited-state absorption in thulium-doped materials in the near-infrared.

Excited-state absorption (ESA) is a key process for upconversion pumping schemes of thulium (Tm) doped laser materials. We have systematically studied two ESA transitions in the near-infrared spectral range, namely F → F (at ∼1 µm) and F → H (at ∼1.5 µm), in various Tm-doped fluoride (ZBLAN glass, cubic KYF and CaF, tetragonal LiYF and LiLuF, monoclinic BaYF crystals) and oxide (cubic YAlO, orthorhombic YAlO crystals) laser materials, using a pump-probe method with a polarized light.

Thermal lensing, heat loading and power scaling of mid-infrared Er:CaF lasers.

Mid-infrared Er:CaF laser operating on the I → I transition is developed. Its power scaling capabilities and thermo-optics (fractional heat loading and thermal lensing) are compared under pumping into the I and I states. Using a 4.

Er:KYF laser at 2.80 µm.

We report on the mid-infrared laser operation of a cubic 15 at.% : crystal. In the quasi-continuous-wave regime, the peak power reaches 255 mW at 2.

Watt-level europium laser at 703 nm.

We report on a watt-level highly efficient europium laser operating at the ${^5{\rm D}_0 \to {^7}{\rm F}_4}$ transition. It is based on the stoichiometric ${\rm KEu}{({\rm WO}_4)_2}$ crystal. Under pumping by a green laser at 532.