A pair of adjacent transmissive diffractive optical elements (DOEs) forms a combined DOE with tunable optical properties, as, for example, a diffractive lens with an adjustable focal length. The optical properties are controlled by a relative movement of the two DOEs, such as a translation or a rotation around the optical axis. Here we discuss various implementations of this principle, such as tunable diffractive lenses, axicons, vortex plates, and aberration correction devices. We discuss the limits of the tuning range and of diffraction efficiency. Furthermore, it is demonstrated how chromatic aberrations can be suppressed by using multi-order DOEs.

中文翻译：

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由相对旋转控制的具有可调光学特性的组合衍射光学元件：教程

一对相邻的透射衍射光学元件 (DOE) 形成具有可调光学特性的组合 DOE，例如具有可调焦距的衍射透镜。光学特性由两个 DOE 的相对运动控制，例如绕光轴平移或旋转。在这里，我们将讨论该原理的各种实现方式，例如可调衍射透镜、轴棱镜、涡流板和像差校正设备。我们讨论了调谐范围和衍射效率的限制。此外，还演示了如何通过使用多阶 DOE 来抑制色差。