Understanding wide field-of-view metalenses

Wide field-of-view (FOV) functionality is crucial for implementation of advanced optical devices with applications spanning medical imaging, 3-D sensing, projection display, and security surveillance. While conventional wide FOV operation relies upon complicated assembly of multiple lens elements, metasurface optics offer a compelling alternative to realize compact, light-weight, and high-performance wide FOV optical modules. Here we elucidate the physical principles and design guidelines which underlies our recent demonstration of a fisheye metalens with > 170˚ diffraction-limited FOV. An analytical model is discussed, and wide-FOV achromatic metalens designs developed with a combination of direct search optimization and deep learning algorithms is presented.