If the lens is bi-convex or plano-convex, a collimated beam of light passing through the lens converges to a spot (a focus) behind the lens. In this case, the lens is called a positive or converging lens. The distance from the lens to the spot is the focal length of the lens, which is commonly abbreviated “f” in diagrams and equations.
If the lens is biconcave or plano-concave, a collimated beam of light passing through the lens is diverged (spread); the lens is thus called a negative or diverging lens. The beam, after passing through the lens, appears to emanate from a particular point on the axis in front of the lens. The distance from this point to the lens is also known as the focal length, though it is negative with respect to the focal length of a converging lens.
Meniscus lenses have two curved surfaces one of which is protrusive while other is intrusive, also these lenses are referred to as convex-concave lenses. Radii of curvature of both surface can be chosen independently from each other. Meniscus lenses find application in optical systems, where aberrations need to be minimized, for instance in multi lens focusing objective, where it helps to minimize focal spot of the beam. The same benefit is applied in collimators. Another advantage is that meniscus design allows to make longer focal length lenses than the ones available in Plano-convex design. Lenses with equal radii of curvature on opposite sides serve well as substrates for resonator mirrors.
An achromatic lens or achromat is a lens that is designed to limit the effects of chromatic and spherical aberration. Achromatic lenses are corrected to bring two wavelengths (typically red and blue) into focus in the same plane.
The most common type of achromat is the achromatic doublet, which is composed of two individual lenses made from glasses with different amounts of dispersion. Typically, one element is a negative (concave) element made out of flint glass such as F2, which has relatively high dispersion, and the other is a positive (convex) element made of crown glass such as BK7, which has lower dispersion. The lens elements are mounted next to each other, often cemented together, and shaped so that the chromatic aberration of one is counterbalanced by that of the other.
Rod lenses are polished on the circumference and ground on both ends. Optical performance is similar to a cylinder lens. Collimated light passing through the diameter of the rod will be focused into a line. These components are used in a variety of laser and imaging applications.
A cylindrical lens is a lens which focuses light into a line instead of a point, as a spherical lens would. The curved face or faces of a cylindrical lens are sections of a cylinder, and focus the image passing through it into a line parallel to the intersection of the surface of the lens and a plane tangent to it. The lens compresses the image in the direction perpendicular to this line, and leaves it unaltered in the direction parallel to it (in the tangent plane). In a light sheet microscope, a cylindrical lens is placed in front of the illumination objective to create the light sheet used for imaging.
Optical Prisms are used to redirect light at a designated angle. Optical Prisms are ideal for ray deviation, or for adjusting the orientation of an image. An Optical Prism’s design determines how light interacts with it. When light enters an Optical Prism, it either reflects off an individual surface or several surfaces before exiting, or is refracted as it travels through the substrate. For example, when light enters a right angle prism, it reflects off a single surface, causing the light to redirect at 90°. When light enters a wedge prism, though, a change in substrate thickness causes the light to deviate through refraction.
Zhuorui offers a wide range of Optical Prisms in a variety of designs, substrates, or coating options. Designs include Right Angle, Amici, Penta, Schmidt, Wedge, Anamorphic, Equilateral, Dove, or Rhomboid prisms and so on.