Photonics Dictionary

Color correcting; chromatic aberration corrected.

A lens consisting of two or more elements, usually of crown and flint glass, that has been corrected for chromatic aberration with respect to two selected wavelengths. Also known as achromat.

A compound lens combination whose astigmatic difference is zero for one or more off-axis zones in the image plane. In such a lens the other aberrations are sufficiently well-corrected to yield...

Also known as aplanatic lens. A lens corrected for spherical aberration and coma.

An aspheric lens is a type of lens whose surface profiles deviate from the traditional spherical shape. Unlike spherical lenses, which have a constant curvature across their surfaces, aspheric lenses...

An astronomical telescope is a type of optical instrument designed to gather and magnify light from distant celestial objects for observation and analysis. It typically consists of two main optical...

Chromatic aberration is an optical phenomenon that occurs when different wavelengths (colors) of light are refracted by a lens or optical system, leading to a failure to focus all colors to the same...

A microscope eyepiece designed for use with apochromatic objectives. Since apochromatic objectives are undercorrected for lateral color, these eyepieces are overcorrected for that aberration.

The simplest lens in which all primary aberrations may be corrected. It consists of two positive crown elements on either side of, and spaced away from, a negative flint element.

A compound lens, the dimensions and materials of which have been so chosen that the lens is appreciably free of aberrations.

A lens with aberrations corrected to the point that residual wavefront errors are substantially less than one-quarter the wavelength of the energy being acted upon.

Secondary aberrations remaining after the primary (Seidel) aberrations have been corrected.

Refers to the characteristic hue of the ocean according to the presence and concentration of specific minerals or substances, such as chlorophyll. Atmospheric aberrations of color must be corrected...

An optical system that is corrected for distortion and spherical aberration and therefore forms the image of a straight line as a straight line.

A camera that consists of a concave spherical mirror with an aspheric plate situated at the center of curvature of the mirror. The purpose of the plate is to correct the spherical aberration of the...

An aberration that remains after primary color is corrected. Primary color causes the back focus of a lens to vary with wavelength; for example, blue light comes to focus closer to the lens than...

A symmetrical, very wide-angle lens. Well-corrected for spherical aberration and color, the Topogon can cover fields up to 90° at speeds from f/11 to f/6.3.