What are lenses?

Lenses are used to focus or disperse light through the use of curved surfaces of a specific medium.  Typically lenses are made of glass but they can also be made of other transparent materials like plastic or crystalline materials.  The first lenses were simple magnifying glasses that were used to read small text and through trial and error evolved into a primitive version of the reading glasses many use today.  Applications for lenses are exceptionally diverse but the most common uses today are for Microscopy, Laser Machining, Sensing, Machine Vision, Satellite Imaging and Astronomy.  Some of the most common types include spherical lenses, aspherical lenses, achromatic lenses, cylindrical lenses, Fly-Eye lenses, and anamorphic lenses.

Utalising two different lenses. One concave and convex, it allows us to create a beam expansion effect. This is what Beam expanders are. Click the picture below to find out more on Beam Expanders

Beam focusing utilises plano convex lenses to create a smaller spot size by focusing the laser beam. Something that utilises beam focusing is an objective lens. Click the picture below to find out more about objective lens.