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arXiv · 2602.02463

Numerically optimized FROG results for the study of red-shifted spectra in multi-frequency Raman generation

Sakthi Priya Amirtharaj·Zujun Xu·Donna Strickland·Borun Chowdhury·Sagnik Acharya·Priyam Samantray·Anil Prabhakar·Kisor Kumar Sahu·Franz Bamer·S. Swayamjyoti
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Abstract

When multifrequency Raman scattering is driven in the transient regime by two chirped pump pulses, the resulting anti-Stokes orders exhibit asymmetric spectral broadening toward lower frequencies, leading to a characteristic double-peaked structure in each order. In this Letter, frequency-resolved optical gating (FROG) is used to investigate the spectral evolution of the first anti-Stokes Raman component. To interpret the observed features, we introduce a double-pulse interference model and employ an adaptive learning-based reconstruction algorithm using the Adam optimizer to retrieve the temporal field evolution. The simulation results show good agreement with the experimental measurements. Our analysis indicates that the observed red-shifted spectral component originates from linear Raman processes within the two-photon dressed-state framework.

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Sakthi Priya Amirtharaj, Zujun Xu, Donna Strickland, Borun Chowdhury, Sagnik Acharya, Priyam Samantray, Anil Prabhakar, Kisor Kumar Sahu, Franz Bamer, S. Swayamjyoti. 2026-02-02. Numerically optimized FROG results for the study of red-shifted spectra in multi-frequency Raman generation. https://arxiv.org/abs/2602.02463

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