Low-threshold, highly efficient Gd3+, Lu3+ co-doped KY(WO4)2:Yb3+ planar waveguide lasers
✍ Scribed by D. Geskus; S. Aravazhi; E. Bernhardi; C. Grivas; S. Harkema; K. Hametner; D. Günther; K. Wörhoff; M. Pollnau
- Publisher
- John Wiley and Sons
- Year
- 2009
- Tongue
- English
- Weight
- 141 KB
- Volume
- 6
- Category
- Article
- ISSN
- 1612-2011
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✦ Synopsis
High-quality crystalline KY(WO 4 ) 2 :Yb 3+ layers codoped with large concentrations of optically inert Gd 3+ and Lu 3+ ions were grown by liquid phase epitaxy. Continuous-wave laser operation in a planar waveguide configuration was observed at 1025 nm. For 23% output coupling, a maximum output power of 195 mW was obtained; a slope efficiency of 82.3% was derived, which to the best of our knowledge is the highest value yet reported for a planar waveguide laser to date. For 1.7% output coupling, a laser threshold as low as 18 mW of absorbed pump power was achieved, which is largely due to the enhanced refractive index contrast of ∼ 7.5×10 -3 between the active layer and the undoped KY(WO 4)2 substrate attained by the co-doping, leading to well-confined pump and laser modes.