Metalenses and Meta-mirrors

Abstract

Lenses are the fundamental optical components and play the key roles in most of the optical systems, including cameras, microscopes, telescopes, projective lithographic machines, and spectrometers. Traditional lenses are made from materials such as glass or plastic and are polished or molded to desired shapes. However, the traditional refractive/reflective or diffractive lenses have their intrinsic limits in integration, weight, chromatic aberration, among others. The newly emerging metalenses may be promising alternatives to overcome these limits for practical applications. In this chapter, we will start with a brief review of the traditional lens in Sect. 9.1. Then, the design methods of the planar metalens and meta-mirror in EO 2.0 are introduced in Sect. 9.2. In Sects. 9.3 and 9.4, planar lenses with large numerical aperture (NA) and wide field of view, which are extremely difficult to realize in traditional optics with compact volume, are discussed in detail. Important technologies and the latest developments in metalenses, including achromatic or super-chromatic imaging, and tunable imaging, are elaborated and highlighted in Sects. 9.5 and 9.6. At last, we also give a brief introduction of nonlinear metalens in Sect. 9.7.