Fast and secure sharing of information is among the prime concerns of almost any communication system. While commonly used cryptographic algorithms cannot provide unconditional security, high-dimensional (HD) quantum key distribution (QKD) offers an exceptional means to this end. Here, we provide a tutorial to demonstrate that HD QKD protocols can be implemented in an effective way using optical elements that are known to most optics labs. We use spatial modes of light as our HD basis and show how to simulate QKD experiments with bright classical light, fostering its easy implementation for a more general audience including industry laboratories or laboratory classes in university teaching and in advanced laboratories for validation purposes. In particular, we use orbital angular momentum Bessel–Gaussian modes for our HD QKD demonstration to illustrate and highlight the benefits of using spatial modes as their natural Schmidt basis and self-healing feature.

中文翻译：

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具有空间光模式的高维密码：教程

快速和安全的信息共享是几乎所有通信系统的主要问题。尽管常用的密码算法无法提供无条件的安全性，但高维（HD）量子密钥分发（QKD）为此提供了一种特殊的方法。在这里，我们提供了一个教程来演示HD QKD协议可以使用大多数光学实验室已知的光学元件以有效的方式实现。我们使用光的空间模式作为高清的基础，并展示了如何使用明亮的古典光模拟QKD实验，从而为更广泛的受众（包括大学实验室的工业实验室或实验室班级以及用于验证目的的高级实验室）实现了轻松实现。尤其是，