Laser-induced polarization-dependent birefringence in oxide glasses

• Applicant: Dr. Andriy Lotnyk
• Subject Area: Synthesis and Properties of Functional Materials
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 448667535

Discovery of femtosecond laser-induced inscription of nanostructures in fused silica (known as nanogratings structures) has opened a way for the engineering of optical components with controlled patterns of birefringence, including polarization converters, holographic media and ultrastable optical memories with multilevel encoding in birefringence parameters. Besides fused silica, a wide variety of glasses shows similar polarization-dependent birefringence. The involved processes are, however, accompanied by more complicated structural and chemical transformations, which are related to different physical effects than in fused silica. Therefore, in order to shed light on the underlying transformations, the proposed project aims to study the influence of composition and structure of different oxide glasses on the formation of polarization-dependent birefringence induced by femtosecond laser pulses. The origins of polarization-dependent birefringence in pure and multicomponent silicate and phosphate glass-forming systems will be investigated in detail. The selected glass systems will allow the realization of various cases of laser-induced polarization-dependent birefringence formation. Advanced facilities of high-precision treatment of glass materials by femtosecond laser pulses will enable accurate experiments on controlled structural modification of the glasses in the wide range of laser processing parameters, while optical characterization will permit detailed investigation of polarization-dependent birefringence in the materials. Combination of different analytical methods will provide the information on local structure and composition of laser-modified samples, while in situ experiments in an electron microscope should give insights into structural and chemical transformations of the studied materials on the nanoscale. The obtained data will allow the determination of material and processing parameters responsible for the polarization-dependent birefringence in the oxide glasses and the development of an efficient approach of controlled polarization-dependent birefringence in similar systems. The comprehensive understanding of origins of the birefringence in oxide glasses will permit the development of system elements with elaborate birefringence archetypes for optics, photonics and optical data storage applications.

• DFG Programme: Research Grants
• International Connection: Russia
• Partner Organisation: Russian Foundation for Basic Research
• Cooperation Partner: Professor Dr. Sergey Lotarev