Structural and waveguiding characteristics of Er3+:Yb3Al5−yGayO12 films grown by the liquid phase epitaxy

• Er:Yb3Al5−yGaxO12 thick films have been successfully grown by LPE.
• The film composition was determined using the high resolution XRD, PIXE and PIGE.
• Gallium substitution is necessary to obtain a waveguide structure in this system.

Erbium (Er3+) doped ytterbium garnet (Er:Yb3Al5−yGayO12; y = 0, 0.55 and 1.1) single crystalline thick films have been grown by the low-temperature liquid phase epitaxy method (LPE). The composition of the films was determined using the high resolution XRD, the particle-induced X-ray emission spectroscopy (PIXE) and the particle-induced gamma-ray emission spectroscopy (PIGE). The lattice mismatch between films and substrates was investigated by the high-resolution X-ray diffraction. The surface analysis was carried out by the atomic force microscopy (AFM). Pure infrared emission of Er3+ ions was observed in all films containing gallium. The characteristics such as refractive index, thickness and light propagation were studied by the m-line spectroscopy (MLS) using several wavelengths (633, 964, 1311 and 1552 nm). All samples, where y = 1.1, were multimode waveguides. For these reasons, the Er:Yb3Al3.9Ga1.1O12 seems to be a promising material for light amplifiers in the IR region.