Optical domes are lenses with two concentric spherical surfaces. Sometimes they are referred to as bent plane parallel plates. Consequently it is usual to define parallelism between two surfaces as the maximum thickness variation between the two surfaces.

A double concave lens/mirror has a negative focal length, thereby causing collimated incident light to diverge. The double concave lens/mirror has an equal radius of curvature on both sides of the lens. They are generally used to expand light or increase focal length in the existing system, such as beam expander and projection systems.

A compound eye lens array is a two-dimensional array composed of multiple independent optical elements

Optical lens from the focal length can be divided into short focus lens, medium focus lens, telephoto lens; From the field of view size, there are wide Angle, standard, telephoto lens;

A pyramidal prism/angular cube reflector is always used to reflect a beam of light into the prism, regardless of the direction of the beam. Corner prisms are widely used where accurate alignment is difficult.

ZnSe lenses are precision optical components commonly used in thermal imaging, high power CO 2 laser systems and life sciences.