A lenslet is literally a small

lens A lens is a transmissive optical device that focuses or disperses a light beam by means of refraction. A simple lens consists of a single piece of transparent material, while a compound lens consists of several simple lenses (''elements'') ...

. The fact that distinguishes it from a small lens is that it is part of a lenslet array. A lenslet array consists of a set of lenslets in the same plane. Each lenslet normally has the same

focal length The focal length of an Optics, optical system is a measure of how strongly the system converges or diverges light; it is the Multiplicative inverse, inverse of the system's optical power. A positive focal length indicates that a system Converge ...

. Lenslets have many uses. One of the key applications for lenslets is in

integral imaging Integral imaging is a three-dimensional imaging technique that captures and reproduces a light field by using a two-dimensional array of microlenses (or lenslets), sometimes called a fly's-eye lens, normally without the aid of a larger overall Obje ...

and light field displays. Lenslets are commonly found in Shack–Hartmann wavefront sensors and beam homogenization optics for projection systems.

References

Lenses {{optics-stub