Characterization of localized circularly polarized THz electric fields using MAPbI3 thin films

IF 3.8 2区物理与天体物理 Q2 PHYSICS, APPLIED

Applied Physics Letters Pub Date : 2026-10-12 DOI:10.1063/5.0351260

Hiroshi Watanabe,Zhenya Zhang,Ai Shimazaki,Tomoya Nakamura,Atsushi Wakamiya,Hideki Hirori

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引用次数: 0

Abstract

Circularly polarized (CP) terahertz (THz) fields are promising for controlling angular momentum in solids. While resonator structures can be used to enhance THz electric fields, a highly localized enhancement makes it difficult to accurately characterize the amplitude and polarization of the local near-field maximum using thick electro-optic crystals. We demonstrate a local probing method based on a band edge modulation in methylammonium lead iodide (MAPbI3) perovskite thin films. The THz-induced transmittance change, ΔT, in the near-infrared (as well as the reflectance change, ΔR) can be used to determine the near-field amplitude, while the degree of the modulation of ΔT (or ΔR) due to the oscillating THz electric-field vector yields the ellipticity ε. The extracted ellipticity is close to the ideal value (within ±0.05) for ε > 0.4. A comparison with finite-difference time-domain simulations shows that this method can be used to characterize the amplitude and ellipticity of the enhanced CP field in the gap of a crosshair resonator with good accuracy. The simulations also reproduce the experimentally observed long-lived near-field waveform well and indicate that the observed difference between the theoretical and experimental ε mainly arises from a probe spot that is slightly displaced from the gap center by about 1 μm. Since this resonator structure has an enhancement factor of 11.8 ± 0.3 and a high preservation of circularity, the combination of this resonator with the proposed probing method should be useful for studies using strong THz fields.

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用MAPbI3薄膜表征局域圆极化太赫兹电场

圆极化（CP）太赫兹（THz）场有望控制固体中的角动量。虽然谐振器结构可以用来增强太赫兹电场，但高度局域化的增强使得使用厚电光晶体精确表征局部近场最大值的振幅和极化变得困难。我们在甲基碘化铅（MAPbI3）钙钛矿薄膜中展示了一种基于能带边缘调制的局部探测方法。太赫兹诱发的近红外透射率变化ΔT（以及反射率变化ΔR）可用于确定近场振幅，而太赫兹电场矢量振荡对ΔT（或ΔR）的调制程度产生椭圆率ε。提取的椭圆度接近ε &；gt的理想值（±0.05以内）；0.4. 与时域有限差分仿真结果的比较表明，该方法可以较准确地表征十字准星腔隙中增强CP场的振幅和椭圆度。实验结果表明，ε的理论值与实验值之间的差异主要是由于探针点偏离间隙中心约1 μm引起的。由于该谐振腔结构具有11.8±0.3的增强因子和较高的圆度保持性，因此该谐振腔与所提出的探测方法的组合将有助于使用强太赫兹场的研究。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Applied Physics Letters 物理-物理：应用

CiteScore

6.40

自引率

10.00%

发文量

1821

审稿时长

1.6 months

期刊介绍： Applied Physics Letters (APL) features concise, up-to-date reports on significant new findings in applied physics. Emphasizing rapid dissemination of key data and new physical insights, APL offers prompt publication of new experimental and theoretical papers reporting applications of physics phenomena to all branches of science, engineering, and modern technology. In addition to regular articles, the journal also publishes invited Fast Track, Perspectives, and in-depth Editorials which report on cutting-edge areas in applied physics. APL Perspectives are forward-looking invited letters which highlight recent developments or discoveries. Emphasis is placed on very recent developments, potentially disruptive technologies, open questions and possible solutions. They also include a mini-roadmap detailing where the community should direct efforts in order for the phenomena to be viable for application and the challenges associated with meeting that performance threshold. Perspectives are characterized by personal viewpoints and opinions of recognized experts in the field. Fast Track articles are invited original research articles that report results that are particularly novel and important or provide a significant advancement in an emerging field. Because of the urgency and scientific importance of the work, the peer review process is accelerated. If, during the review process, it becomes apparent that the paper does not meet the Fast Track criterion, it is returned to a normal track.