Solitons are wave packets that can propagate without changing shape by balancing nonlinear effects with the effects of dispersion. In photonics, they have underpinned numerous applications, ranging from telecommunications and spectroscopy to ultrashort pulse generation. Although traditionally the dominant dispersion type has been quadratic dispersion, experimental and theoretical research in recent years has shown that high-order, even dispersion enriches the phenomenon and may lead to novel applications. In this Tutorial, which is aimed both at soliton novices and at experienced researchers, we review the exciting developments in this burgeoning area, which includes pure-quartic solitons and their generalizations. We include theory, numerics, and experimental results, covering both fundamental aspects and applications. The theory covers the relevant equations and the intuition to make sense of the results. We discuss experiments in silicon photonic crystal waveguides and in a fiber laser and assess the promises in additional platforms. We hope that this Tutorial will encourage our colleagues to join in the investigation of this exciting and promising field.

中文翻译：

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纯四次孤子及其推广——理论与实验

孤子是波包，通过平衡非线性效应和色散效应，可以在不改变形状的情况下传播。在光子学中，它们支持了许多应用，从电信和光谱到超短脉冲生成。尽管传统上主要的色散类型是二次色散，但近年来的实验和理论研究表明，高阶均匀色散丰富了这种现象并可能带来新的应用。在针对孤子新手和经验丰富的研究人员的本教程中，我们回顾了这个新兴领域的令人兴奋的发展，其中包括纯四次孤子及其推广。我们包括理论、数值和实验结果，涵盖基本方面和应用。该理论涵盖了相关方程和理解结果的直觉。我们讨论了硅光子晶体波导和光纤激光器的实验，并评估了其他平台的前景。我们希望本教程将鼓励我们的同事加入这个令人兴奋和充满希望的领域的调查中。