TY - JOUR N2 - In this paper the overview of the recent study on the rare-earth activated waveguides performed in the Optoelectronic Department of IMiO is presented. We reported on the development of rare earth-doped fluorozirconate (ZBLAN) glass fibers that allow a construction of a new family of visible and ultraviolet fiber lasers pumped by upconversion. Especially the performance of holmium devices is presented. The properties of laser planar waveguides obtained by the LPE process and the growth conditions of rare earths doped YAG layers are presented. In this paper we present also the theoretical study of the nonlinear operation of planar waveguide laser, as an example the microdisk Nd:YAG structure is discussed. We derived an approximate formula which relates the small signal gain in the Nd:YAG active medium and the laser characteristics, obtained for whispering-gallery modes and radial modes, to the output power and real parameters of the laser structure L1 - http://www.czasopisma.pan.pl/Content/111757/PDF/(53-2)97.pdf L2 - http://www.czasopisma.pan.pl/Content/111757 PY - 2005 IS - No 2 EP - 102 KW - waveguide lasers KW - laser materials KW - spectroscopy KW - upconversion KW - rare-earth ions A1 - Woliński, W. A1 - Malinowski, M. A1 - Mossakowska-Wyszyńska, A. A1 - Piramidowicz, R. A1 - Szczepański, P. VL - vol. 53 DA - 2005 T1 - Investigation and modelling of rare-earth activated waveguide structures SP - 97 UR - http://www.czasopisma.pan.pl/dlibra/publication/edition/111757 T2 - Bulletin of the Polish Academy of Sciences Technical Sciences ER -