The objective of the fellowship is twofold: first, gaining new fundamental knowledge on the phenomena underlying the process of glass modification upon irradiation by femtosecond (fs) pulses, and second, application of this knowledge to optimise glass composition, the process of photo-fabrication, and finally to the design and fabrication of novel devices. Although fs writing has already been applied to create a variety of guiding structures, there is no proper understanding of its general application and, indeed, no demonstrations of the efficient use of this technique in the fabrication of devices which cannot be realised by conventional technologies. Novel laser designs are important to overcome the drawbacks of existing schemes of fs fiber lasers, as well as to develop quite novel fs waveguide lasers based on the principle of Kerr lens mode locking, previously used in bulk solid-state lasers. The Fellow has suggested to use the effect of power leakage on waveguide discontinuities in combination with the self-focusing effect in order to develop intra-cavity elements for fs fiber lasers and waveguide lasers. Two novel glass systems (both in rare earth doped and undoped forms), offering greater optical versatility than high silica glasses, will be investigated: chalcogenide glasses and tellurite glasses. Modelling of the modification process with the use of an approach developed by the proposed Fellow will consider it as the result of the co-operative action of photostructural phenomena, diffraction and non-linear effects. The relevance of the fellowship to the specific objectives of the action is a basis for long-term collaborations between two host institutions, for stimulating national investments into the development of novel technologies in Russia, for stimulating greater mobility of researchers, for promoting the participation of women in science decision-making and policy definition, particularly, for the Fellows career development.