Speaker
Description
The polarization state of few-cycle laser pulses plays a fundamental role in light–matter interactions, governing phenomena such as optomagnetic effects, high-harmonic generation, and coherent control. Accurate characterization of the time-dependent polarization of ultrashort pulses is therefore essential for both optimizing these applications and gaining insight into the underlying physical processes. Diverse techniques for the characterization of the polarization state of ultrashort laser pulses have been developed, such as single-channel 1 or dual-channel spectral interferometry [2], tomographic ultrafast retrieval of transverse light E-fields (TURTLE) [3], V-FROG [4] or a recently reported extension of the dispersion-scan (d-scan) technique in which a polarization gate is temporally characterized [5].
Here, we present D-TURTLE [6], a novel technique for the complete characterization of the time-resolved polarization state of few-femtosecond laser pulses. The method combines dispersion scan (d-scan) with the Tomographic Ultrafast Retrieval of Transverse Light E-fields (TURTLE) approach in a robust, self-referenced, and inline configuration. D-TURTLE retrieves the full temporal polarization dynamics, the relative temporal delay between polarization components, and the handedness of the polarization vector.
D-TURTLE is based on recording four d-scan traces corresponding to four different projections of the electric field onto the fixed axis of a nonlinear crystal optimized for second-harmonic generation of linearly polarized light. Two orthogonal projections are first independently retrieved using conventional d-scan algorithms to obtain the two polarization components. A dedicated retrieval algorithm, specifically developed for D-TURTLE, then exploits the remaining projections and simultaneously minimizes two error functions to unambiguously determine the relative phase and temporal ordering of the polarization components. Unlike conventional FROG, d-scan, or FROG-based TURTLE approaches, this strategy uniquely resolves the complete polarization state.
Numerical simulations and experimental measurements demonstrate that D-TURTLE unambiguously reconstructs the time-resolved polarization state of few-cycle pulses, including the relative temporal position of the polarization components (even if the polarization components do not overlap in time) and the instantaneous handedness of the polarization vector. The combination of robustness, self-referencing operation, and inline implementation makes D-TURTLE a powerful and practical tool for the complete characterization of ultrafast vector laser pulses, specially in the few-cycle regime.
Notes and References
1 Alonso, B.; Sola, Í. IEEE J. Sel. Top. Quantum Electron. 2019, 25, 1-7
2 Walecki, W. J.; Fittinghoff D. N.; Smirl A. L.; Trebino R. Opt. Lett. 1997, 22, 81-83
3 Schlup P.; Masihzadeh, O; Xu L.; Trebino R.; Bartels R. A. Opt. Lett. 2008, 33, 267-269
4 Haham G. I.; Levin A.; Sidorenko P.; Lerner G.; Cohen O. J. Phys: Photonics 2021, 3, 034017
5 Rivas, D. D.; Raab A. K.; Guo C.; Viotti A. L.; Sytcevich I.; L´Huillier A.; Arnold C. J. Phys: Photonics 2024, 6, 015003
6 Pérez-Benito Ó.; Weigand R. Opt. Laser Technol. 2024, 179, 111273