Spherical Lenses: Have surfaces that are parts of a sphere, used for focusing light into a point or diverging it uniformly. These are the most common types of simple lenses
Cylindrical Lenses: Have a cylindrical shape and focus light into a line rather than a point. They are commonly used in laser optics and beam shaping applications
Aspheric Lenses: These have non-spherical surfaces designed to reduce spherical aberrations and improve image quality in high-performance optical systems like cameras and telescopes
Achromatic Lenses: Composed of two or more elements made from different types of glass to correct chromatic aberration (the failure of a lens to focus all colors at the same point)
Special Types
Gradient Index (GRIN) Lenses: These lenses have varying refractive indices across their material, which allows them to bend light gradually rather than abruptly at the surface. They are often used in fiber optics and compact imaging systems
Axicon Lenses: Axicon lenses are cone-shaped optical components that transform a collimated light beam into a ring or a Bessel beam. Unlike traditional lenses, which focus light to a point, axicons create a line focus or ring-shaped beam. They are commonly used in laser applications such as optical trapping, laser eye surgery, and materials processing
Powell Lenses: Powell lenses are cylindrical aspheric lenses designed to convert a Gaussian laser beam into a uniform-intensity line. They redistribute light from the center to the edges of the beam, eliminating the central “hot spot” typical of Gaussian beams. These lenses are widely used in machine vision, barcode scanning, and flow cytometry
Fresnel Lenses: Fresnel lenses are lightweight and thin compared to traditional lenses due to their concentric ring design. They focus light efficiently with less material and are commonly used in lighthouses, solar concentrators, and imaging systems where weight and size are critical factors
Diffractive Optical Elements (DOEs): DOEs use microstructures to manipulate light by diffraction, allowing them to perform complex functions like beam shaping or splitting. They are used in laser material processing, holography, and optical metrology for creating specific intensity patterns
