An introduction to custom optics and spherical lenses
Posted by juliabennet on July 21st, 2013
Given the fact that any transparent piece of material with at least one curved surface acts as a lens, approaching custom optics for achieving specific results is mandatory. Consequently, our topic for today will be spherical lenses, some of the most common types used in a wide range of optical equipments.
If lenses have one or both of their surfaces curved, the nature of the curvature is essential in determining the type of lens. The spherical ones, we are now talking about, should have at least one of their active surfaces spherical, the second one being either plano or spherical.
They make the base of so many technologies and devices simply because they have an affordable manufacturing technology and they insure the effects that various optical schematics impose. Whenever the requirements permit, allow or demand it, a spherical lens is preferred to any alternative. Otherwise, aspheric lenses are used instead, even though their technology is considerably more expensive and demanding in practice.
From an optical perspective, spherical lenses present the following features: the object and image focal distances, the object and image front focal distances, the image and object’s main plane abscissas, the distance between the main planes, the diameter and the refractive index.
From a geometrical perspective, these lenses are characterized by the curvature radii, the central and edge thickness, the overall diameter respectively the size of the facets. Knowing all these features allows specialists to resort to various custom optics strategies and insure different facilities of the numerous technologies.
If you take a look into the functioning principles of the main optical devices, you will realize that simple lenses are used as such only in very rare circumstances. In general, combining different lenses, with different curvatures, diameters or refractive indexes is the norm.
Now if you were thinking that this is the entire theory that can be attributed to these lenses, think again! So far, we have only discussed the aspects related to curvature, yet we said nothing about the optical effects. Upon this feature, we can classify the spherical lenses into convergent, divergent and neutral lenses. The first ones have the focal distance higher than zero and the second ones have it lower than zero.
Even so, completely different shapes can construct lenses that share the same power. Consequently, convergent or positive lenses can be biconvex, plano-convex or meniscus-convergent or positive meniscus. In the same way, divergent lenses can be biconcave, plano-concave or meniscus-divergent or negative meniscus.
Easy to imagine, every single one of them comes with tens of individual features. Knowing them all is essential for setting the most appropriate combinations. Even though contact lenses, eyeglasses, magnifying glasses, telescopes and binoculars, microscopes, projectors and cameras all include optical devices, knowing how to set up the assemblies behind them is essential!
Whenever one of your devices stopped functioning, consulting a professional in order to determine what kind of lenses should be replaced is essential. Otherwise, you might find yourself a little bit overwhelmed by all the features that these lenses should achieve.
If you are looking for custom optics services, you have come to the right place. From plain spherical lenses to complicated optical assemblies, you can have them all!