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arXiv · 2301.02910

Universality in odd-even harmonic generation and application in terahertz waveform sampling

Doan-An Trieu·Ngoc-Loan Phan·Quan-Hao Truong·Hien T. Nguyen·Cam-Tu Le·DinhDuy Vu·Van-Hoang Le
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Abstract

Odd-even harmonics emitted from a laser-target system imprint rich, subtle information characterizing the system's dynamical asymmetry, which is desirable to decipher. In this Letter, we discover a simple universal relation between the odd-even harmonics and the asymmetry of the THz-assisted laser-atomic system -- atoms in a fundamental mid-IR laser pulse combined with a THz laser. First, we demonstrate numerically and then analytically formulize the harmonic even-to-odd ratio as a function of the THz electric field, the source of the system's asymmetry. Notably, we suggest a scaling that makes the obtained rule universal, independent of the parameters of both the fundamental pulse and atomic target. This universality facilitates us to propose a general pump-probe scheme for THz waveform sampling from the even-to-odd ratio, measurable within a conventional compact setup.

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Doan-An Trieu, Ngoc-Loan Phan, Quan-Hao Truong, Hien T. Nguyen, Cam-Tu Le, DinhDuy Vu, Van-Hoang Le. 2023-01-07. Universality in odd-even harmonic generation and application in terahertz waveform sampling. https://doi.org/10.1103/physreva.108.023109

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