Growth of Nd:Gd₃Ga₅O₁₂ Thin Films by Pulsed Laser Deposition for Planar Waveguide Laser

摘要

Pulsed laser radiation of a KrF excimer laser was used for the deposition of thin Nd3+ dopedGd3Ga5O12 (Nd:GGG) films on yttrium aluminium garnet (YAG) and sapphire single crystalsubstrates. By variation of PLD-parameters such as temperature and processing gas pressure,amorphous and single crystalline thin films were produced. The morphology and the composition ofthe grown films were investigated by optical microscopy, scanning electron microscopy andelectron dispersive X-ray spectroscopy. Thickness and structural properties of the deposited filmswere determined by optical reflection spectroscopy and X-ray diffraction, respectively. The opticalproperties of grown films on different substrates were compared. An amorphous Nd:Gd3Ga5O12 thinfilm on yttrium aluminium garnet was used for demonstration of an infrared waveguide laser. Aplanar wave guiding structure was formed in deposited film between two parallel groovesmicromachined using laser radiation delivered by a femtosecond CPA-Laser-System. The resultingwaveguides were polished and provided with resonator mirrors. With a 5% output coupler at 1064nm, a laser threshold of 1080 mW and 0.2% slope efficiency were obtained.