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Bibliographic Details
Main Author: Shan, Junyi
Format: Preprint
Published: 2024
Subjects:
Online Access:https://arxiv.org/abs/2412.02991
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author Shan, Junyi
author_facet Shan, Junyi
contents Optical nonlinearity, especially the second harmonic generation (SHG), is generally weak in materials but has the potential to be applied in high-speed optical computers and energy-efficient artificial intelligence systems. In order to program such photonic circuits, electrical and all-optical modulation mechanisms of optical nonlinearity have been proposed. Among them the electrical methods are bottlenecked by speed, while optical methods like Floquet engineering provides a fast heat-free route, but has only been experimentally shown to suppress SHG. Here we theoretically and experimentally demonstrated an ultrafast enhancement of SHG by 40% on a timescale of $\sim$ 500 femtosecond in van der Waals NiPS$_3$. We performed single-ion model calculations to show that by optically control the electron occupation of different energy levels, the SHG can be enhanced due to different electronic states involved in the SHG process. We then performed temperature-dependent time-resolved measurements in both linear and nonlinear optics, which confirm our calculations. We also discussed the implications for other materials in the transition metal thiophosphates (MPX$_3$) family.
format Preprint
id arxiv_https___arxiv_org_abs_2412_02991
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Ultrafast giant enhancement of second harmonic generation through level occupation engineering
Shan, Junyi
Strongly Correlated Electrons
Optics
Optical nonlinearity, especially the second harmonic generation (SHG), is generally weak in materials but has the potential to be applied in high-speed optical computers and energy-efficient artificial intelligence systems. In order to program such photonic circuits, electrical and all-optical modulation mechanisms of optical nonlinearity have been proposed. Among them the electrical methods are bottlenecked by speed, while optical methods like Floquet engineering provides a fast heat-free route, but has only been experimentally shown to suppress SHG. Here we theoretically and experimentally demonstrated an ultrafast enhancement of SHG by 40% on a timescale of $\sim$ 500 femtosecond in van der Waals NiPS$_3$. We performed single-ion model calculations to show that by optically control the electron occupation of different energy levels, the SHG can be enhanced due to different electronic states involved in the SHG process. We then performed temperature-dependent time-resolved measurements in both linear and nonlinear optics, which confirm our calculations. We also discussed the implications for other materials in the transition metal thiophosphates (MPX$_3$) family.
title Ultrafast giant enhancement of second harmonic generation through level occupation engineering
topic Strongly Correlated Electrons
Optics
url https://arxiv.org/abs/2412.02991