Optics - Lenses

A lens refers to a curved, transparent material, usually glass, used to refract light and control its path. Lenses are used in applications such as magnifying glasses, eyeglasses, cameras, microscopes, telescopes, and other optical equipment. In the past, lenses have been used to correct vision in humans. Today, lens technology has progressed in the creation of structures that bring unprecedented clarity in focus and image quality.

1030512403 Application Field

Within optics, lenses play a valuable role in controlling light for a variety of applications. Lenses have been used in the field of corrective lenses in the form of eyeglasses for decades. Famously, Benjamin Franklin wearing a pair of “Bi-focal” lenses is a popular image. Lenses are also critical to the functioning of cameras and telescopes, in which light is refracted into viewable images. The imaging capabilities of lenses have advanced significantly over the years, allowing for greater clarity and sharper resolution of objects captured on camera or viewed through a telescope.

Lenses can also be used to split and redirect light in the area of optics known as opto-mechanical systems. In this functionality, an opto-mechanical system uses lenses to project and divide the light beam of a single light source into many discrete paths. Examples of this include stage lighting systems, laser-driven applications, and specialty light tools for video display. In modern day products, some lenses are even integrated directly into electronics and used in things such as projection systems.

1030512403 Working Principle

Undoubtedly, lenses are complex tools and understanding the science behind how they work can help the user better understand their use and limitations. Light is made up of many individual waves that travel through a certain medium (either as empty space or a given object) at a designated velocity. When these light waves pass through a curved lens, the waves interact with the material at an angle and following yet another predetermined velocity.

Depending on the curvature of the lens and the angle at which the light interacts with the surface of the material, the waves can either be bent, or ‘refracted’, to converge at a single point - this could result in an image being formed at the convergence point - or disperse. Generally, when refracting light waves, the curvature of the lens acts as a ‘bend’ in a river, slowing and diverting the light according to the nature of the curvature.

By combining lenses made of different materials and curvatures, light can be manipulated to serve the purpose of your individual application. Combining lens refraction or dispersal with mirrored surfaces, and the addition of further lens types, one can substantially change the image produced by a given set of optics.