Investigation of ultrafast fibre lasers operating on principle of Mamyshev regenerator at short-wave IR wavelength range

• Applicant: Dr. Maria Chernysheva, Ph.D.
• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 450888782

Since early 1990s, ultrafast light sources have become an object for extensive research and industrial interest. Ultrashort pulse lasers, built in all-fibre configuration, benefit from the maintenance-free operation, cost-efficiency and easy fabrication process. Ultrafast lasers serve as a fruitful experimental test-bed for the study of nonlinear wave dynamics, as well as play a significant role in the progress of lightwave technologies for rapidly increasing range of applications. The history of short-wave IR laser systems, operating from 1.7 to 2.5 micrometres, has demonstrated rapid development just over the previous decade, due to the lack of fibre-based components and testing equipment. The proposed project studies underlying physics of Tm-doped fibre lasers built on the principle of Mamyshev regenerator. Such configuration has been recently suggested as an innovative approach for designing laser technology platforms with virtually on-demand performance, as requires just few fibre optic components and features extreme environmental stability, since ultrashort pulse generation is not affected by polarisation.The vision of the proposed project is to investigate both theoretically and experimentally generation of ultrashort pulses in Mamyshev oscillators. Such laser configurations rely on the counterintuitive design of the discontinuous cavity due to offset spectral filtering. Circulation of a pulse in the cavity of such lasers is analogous to propagation through concatenated regenerators, which leads to the formation of ultrashort pulses with significantly suppressed CW breakthrough. The research programme is designed around three inter-related objectives addressing key research challenges: (i) Numerical modelling of Tm-doped fibre Mamyshev lasers, balancing net cavity dispersion and nonlinearity for spectral broadening, and investigation of output laser parameters tuneability range; (ii) Investigation of special glass matrixes for active fibres, development of laser systems and their optimization; (iii) Application of the real-time measurement techniques to examine temporal and spectral dynamics of the laser and to evaluate the feasibility of real-time spectroscopy in application to biosamples analysis at short-wave IR wavelength range. The research of ultrafast Mamyshev Tm-doped fibre lasers will be performed in close collaboration with the theoretical group in Aston University in the UK (Dr A. Perego) and experts in fibre fabrication from Nanyang Technological University in Singapore (Prof. S. Yoo).Therefore, the project fills the gap between theoretical understanding and experimental real-time observation of the coherent pulse formation through instabilities processes in Mamyshev oscillators for the development of advanced systems, which will satisfy current demand on innovative laser sources at short-wave IR wavelength range, offering a broad spectrum of spectroscopic, biomedical, navigation and scientific applications.

• DFG Programme: Research Grants