近日，瑞典查尔姆斯理工大学Andrekson, Peter A.团队研究了使用非线性集成波导的超宽带光放大。这一研究成果发表在2025年4月9日出版的《自然》杂志上。

四波混频是一种非线性光学现象，可用于宽带低噪声光放大和波长转换。它在通信、计算、计量、成像和量子光学中的应用得到了广泛的研究。光集成波导具有占地面积小、非线性大、色散工程能力强等优点，是实现高增益、大带宽四波混频的理想选择，而反常色散是实现这一混频的关键条件。人们已经研究了基于硅、砷化铝镓和非线性玻璃的各种波导，但由于异常色散的传统设计方法会导致多模操作，因此增益和带宽会大幅降低。

研究组提出了一种制造同时具有单模操作和反常色散的非线性波导的方法，用于超宽带操作和高效四波混频。尽管他们在氮化硅波导中实现了这一点，但这种设计方法也可以用于其他平台。通过使用高阶色散，他们在这些超低损耗集成波导中实现了前所未有的超过300nm的放大带宽。在200 nm以上的单个光信道中实现了100 Gbit s^-1数据的无惩罚全光波长转换。这些单模色散工程非线性波导可以成为各种非线性光子学应用中的实用构建块。

附：英文原文

Title: Ultra-broadband optical amplification using nonlinear integrated waveguides

Author: Zhao, Ping, Shekhawat, Vijay, Girardi, Marcello, He, Zonglong, Torres-Company, Victor, Andrekson, Peter A.

Issue&Volume: 2025-04-09

Abstract: Four-wave mixing is a nonlinear optical phenomenon that can be used for wideband low-noise optical amplification and wavelength conversion. It has been extensively investigated for applications in communications1, computing2, metrology3, imaging4 and quantum optics5. With its advantages of small footprint, large nonlinearity and dispersion-engineering capability, optical integrated waveguides are excellent candidates for realizing high-gain and large-bandwidth four-wave mixing for which anomalous dispersion is a key condition. Various waveguides based on, for example, silicon, aluminium gallium arsenide and nonlinear glass have been studied6,7,8,9,10, but suffer from considerable gain and bandwidth reductions, as conventional design approaches for anomalous dispersion result in multi-mode operation. We present a methodology for fabricating nonlinear waveguides with simultaneous single-mode operation and anomalous dispersion for ultra-broadband operation and high-efficiency four-wave mixing. Although we implemented this in silicon nitride waveguides, the design approach can be used with other platforms as well. By using higher-order dispersion, we achieved unprecedented amplification bandwidths of more than 300nm in these ultra-low-loss integrated waveguides. Penalty-free all-optical wavelength conversion of 100Gbits1 data in a single optical channel of over 200nm was realized. These single-mode dispersion-engineered nonlinear waveguides could become practical building blocks in various nonlinear photonics applications.

DOI: 10.1038/s41586-025-08824-3

Source: https://www.nature.com/articles/s41586-025-08824-3