In this Letter, we experimentally demonstrate liquid crystal-based moiré lenses with a wide and tunable focal length by direct-writing photoalignment. Our moiré lenses, which consist of two cascaded diffractive optical elements, have a large range of refractive power between $\pm 0.85\;{{\rm m}^{- 1}}$ at 532 nm and a mutual rotation between $\pm 90^\circ$ with high diffraction efficiency ($\gt\!{75}\%$). Based on the as-designed moiré lenses, we propose high-dynamic-resolution optical edge detection without any axial shift or substitution of components. The minimum edge width is 13.2 µm and can be adjusted within 100 µm by mutual rotation of this device, which has great potential to be used in adaptive and compact optical systems.

中文翻译：

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基于焦距可调的液晶衍射莫尔透镜的高动态分辨率光学边缘检测

在这封信中，我们通过直接写光对准实验性地演示了具有宽且可调焦距的基于液晶的莫尔透镜。我们的莫尔透镜由两个级联的衍射光学元件组成，在532 nm的$ \ pm 0.85 \; {{\ rm m} ^ {-1}} $之间有很大的折光力，并且在$ \ pm 90 ^ \ circ $具有高衍射效率（$ \ gt \！{75} \％$）。基于设计的莫尔透镜，我们提出了一种高动态分辨率的光学边缘检测方法，而无需进行任何轴向偏移或组件替换。最小边缘宽度为13.2 µm，可以通过该设备的相互旋转将其调整在100 µm之内，这在自适应和紧凑型光学系统中具有很大的潜力。