Two-photon absorption and nonlinear refraction of AlN from ultraviolet to near-infrared

IF 3.6 2区物理与天体物理 Q2 PHYSICS, APPLIED

Applied Physics Letters Pub Date : 2025-04-15 DOI:10.1063/5.0260338

Zhong-guo Li, Wenfa Zhou, Zenghua Wang, Datang Xu, Xifeng Yang, Xuekun Hong, Yinglin Song

引用次数: 0

Abstract

We report a detailed characterization of the wavelength dependency of two-photon absorption coefficient β and Kerr nonlinearity n2 in aluminum nitride (AlN) single crystal over a spectral range from 350 to 1030 nm (0.19 < Ephoto/Eg < 0.57). Femtosecond Z-scan results show that the dispersion of β compares favorably with the theoretical prediction at wavelengths shorter than 400 nm (half of bandgap Eg). However, the nonlinear refractive index n2 demonstrated a substantial deviation from theoretical calculations in the 350–450 nm regime, which is correlated with the sub-bandgap absorption band observed in AlN single crystal. The effects of trapped carrier-induced absorption and refraction were determined by femtosecond pump–probe measurements, which could be attributed to the transition from valence band maximum to mid-gap defect states in AlN. Our results provide guidance for developing AlN-based nonlinear integrated photonic devices in the UV–visible spectral range.

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AlN从紫外到近红外的双光子吸收和非线性折射

我们报告了氮化铝（AlN）单晶中双光子吸收系数β和克尔非线性度 n2 在 350 到 1030 nm 光谱范围内（0.19 < Ephoto/Eg < 0.57）的波长依赖性的详细特性。飞秒 Z 扫描结果表明，在波长短于 400 nm（带隙 Eg 的一半）时，β 的色散与理论预测值相当。然而，在 350-450 纳米波段，非线性折射率 n2 与理论计算结果有很大偏差，这与在氮化铝单晶中观察到的亚带隙吸收带有关。飞秒泵浦探针测量确定了困载流子诱导的吸收和折射效应，这可能归因于氮化铝中价带最大态向中隙缺陷态的转变。我们的研究结果为在紫外-可见光谱范围内开发基于氮化铝的非线性集成光子器件提供了指导。

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.