PhD thesis supervisor: dr. Aleksej Rodin (apply for recommendation)
Study of nonlinear scattering-driven pulse compression methods to advance femtosecond laser architectures
The study aims to explore the ultimate compression capabilities of transient stimulated scattering (TSS) configurations employing self-seeding feedback to deliver femtosecond output pulses with energies greater than a few mJ. From such a perspective, the potential of stimulated Brillouin scattering (SBS), as well as backward and forward stimulated Raman scattering (SRS), is still far from being exploited. A comprehensive understanding of the physics of TSS-compression paves the way to reducing the cost of femtosecond lasers by eliminating the need for mode-locking and regenerative amplifiers. Ultrafast lasers based on alternative approaches will find their applications in materials processing, medicine and science. The SBS and backward SRS improve beam quality through phase conjugation. The SRS-related red shift is favorable for nonlinear microscopy and THz generation. In high-field physics, front-end SRS setups ensure orders of magnitude higher temporal contrast of laser pulses due to the inherent threshold nature. This will facilitate the attosecond X-ray sources and laser wakefield acceleration. Moreover, controlling the steepness of the leading or trailing edges in SRS effectively broadens of the pulse spectrum due to self-phase modulation. This paves the way for the transition from hundreds of femtoseconds to just a few optical cycles after compression.