Teoman Gün

Power scaling of laser diode pumped Pr 3+ :LiYF 4 cw lasers: efficient laser operation at 522.6 nm, 545.9 nm, 607.2 nm, and 639.5 nm

We report efficient cw laser operation of laser diode pumped Pr(3+)-doped LiYF4 crystals in the visible spectral region. Using two InGaN laser diodes emitting at λ(P)=443.9 nm with maximum output power of 1 W each and a 2.9-mm-long crystal with a doping concentration of 0.5%, output powers of 938 mW, 418 mW, 384 mW, and 773 mW were achieved for the laser wavelengths 639.5 nm, 607.2 nm, 545.9 nm, and 522.6 nm, respectively. The maximum absorbed pump powers were approximately 1.5 W, resulting in slope efficiencies of 63.6%, 32.0%, 52.1%, and 61.5%, as well as electro-optical efficiencies of 9.4%, 4.2%, 3.8%, and 7.7%, respectively. Within these experiments, laser diode-pumped laser action at 545.9 nm was demonstrated for what is believed to be the first time.

Efficient continuous wave deep ultraviolet Pr3+:LiYF4 laser at 261.3 nm

We report continuous wave deep ultraviolet laser operation at 261.3 nm by intracavity frequency doubling of laser diode pumped Pr3+ doped LiYF4 lasers. Using two InGaN laser diodes with a maximum output power of about 1 W each, a 2.9 mm long Pr3+:LiYF4 crystal and a 5 mm long beta-barium-borate crystal, coherent radiation with an output power of 481 mW at 261.3 nm was achieved at an optical-to-optical efficiency of 26.1% with respect to the total pump power. Both, linear and nonlinear losses have been calculated to be approximately 0.6% by using a model for intracavity frequency doubling with focussed Gaussian beams.

Two-dimensional growth of lattice matched Nd-doped (Gd,Lu)2O3 films on Y2O3 by pulsed laser deposition

This letter focuses on epitaxial growth of a 1-μm-thick lattice matched Nd-doped monocrystalline (Gd,Lu)2O3 film deposited on a {100} oriented Y2O3 substrate by pulsed laser deposition. Layer-by-layer growth indicated by in situ reflection high energy electron diffraction was observed up to film thicknesses of 100nm. The subsequent growth behavior could be explained by a multilevel growth mode. Thus, the growth mode was two-dimensional and epitaxial. Lattice matching of up to 99.3% was achieved. The evolution of the structural and topographical properties of the films was verified by ex situ x-ray diffraction analysis and atomic force microscopy, respectively.

Epitaxial growth by pulsed laser deposition of Er-doped Sc2O3 films on sesquioxides monitored in situ by reflection high energy electron diffraction

In this letter, the authors report on the epitaxial growth by pulsed laser deposition of Sc2O3 and Er(5%):Sc2O3 films on {100} and {111} oriented Sc2O3. They observed layer-by-layer growth in the orientation defined by the substrate. This was indicated by reflection high energy electron diffraction as intensity oscillations of the specularly reflected electron beam. A monolayer-smooth film surface was observed by atomic force microscopy. Such a growth behavior was also achieved during initial growth of Sc2O3 on {100} oriented Y2O3. Additional x-ray diffraction analysis shows good agreement with the growth behavior mentioned above.

Mono-crystalline rare earth doped (Gd, Lu) 2 O 3 waveguiding films produced by Pulsed Laser Deposition and structured by reactive ion etching

Epitaxially grown Nd(0.5%):(Gd, Lu)₂O₃ and Er(0.6%):(Gd, Lu)₂O₃ waveguides deposited on Y₂O₃ by pulsed laser deposition, providing peak emission cross sections comparable with those of Lu₂O₃ bulk crystals, have been fabricated and structured. Rib waveguiding has been shown.

Miniature Lasers on the Basis of Yb:Sc 2 O 3

Yb:Sc2O3 was investigated in a miniature plane-plane resonator and compared with Yb:YAG. A record slope efficiency around 80 % was measured with a 0.1 % Yb-doped 3 mm-rod.

Neodymium and Ytterbium Doped Sapphire Films Grown by Pulsed Laser Deposition

Sapphire films with various dopant concentrations of both neodymium and ytterbium ions were grown by pulsed laser deposition. Reflection high energy electron diffraction and X-ray diffraction measurements indicate epitaxial growth of the films.