Photonics Dictionary

Concave is an adjective used to describe a surface or shape that curves inward or has a hollow or recessed appearance. In the context of geometry or optics, a concave shape is one that curves or...

Concave and convex spherical mirrors are types of curved mirrors that have surfaces shaped like segments of spheres. These mirrors are commonly used in optics for various applications, including...

A reflecting grating ruled on a concave spherical surface that not only disperses the light but focuses the spectrum. The great advantage of this grating lies in the fact that no separate collimating...

The generation of a grating on a concave spherical blank by the holographic process. In this way, ghost images and intense stray light are avoided.

A lens having each of its outer faces curved inward.

A diverging lens with both surfaces concave.

A lens with one plane surface and one concave surface.

A convex, concave or flat cast iron form that is used to shape a soft mold block of optical components.

The center of the sphere of which the surface of a lens or mirror forms a portion. Each curved surface of a lens has a center of curvature; the surfaces may be convex or concave.

A lens with one concave surface and one convex surface; synonymous with meniscus.

An interferometer formed by two similar concave spherical mirrors arranged with the center of one sphere on the other mirror. In this instrument the field is more concentrated by the axis of the...

A converging lens with one convex and one concave surface.

Convex is an adjective used to describe a surface or shape that curves outward, bulges, or has a rounded and outwardly extending appearance. In the context of geometry or optics, a convex shape is...

The concave portion of a surface, formed on a blank, on which the disk of higher refractive glass will be fused to form a multifocal spectacle lens.

A lens aberration in which the focal length varies radially outward from the center of the field. It has the effect of making a straight tangential line in the object appear curved in the image,...

A cylindrical lens is an optical component that has different curvatures along its two orthogonal axes, resulting in a shape resembling a cylinder. Unlike spherical lenses, which have the same...

A form of monochromator optical system consisting of two spherical concave mirrors used in conjunction with a movable diffraction grating.

A concave surface that has too much negative power; i.e., its radius of curvature is too short. This condition can be corrected if material is removed from the center section of the polisher.

A lens with one surface convex and the other concave, the latter having the greater curvature. It also is known as a diverging meniscus lens.

A diverging lens is a type of lens that causes parallel rays of light to spread out or diverge. It is thinner in the center than at the edges and is commonly referred to as a concave lens. The most...

A gas laser equipped with Brewster windows and concave mirrors (having unlike reflective properties) at each end of the tube to produce two separate wavelengths at the same time.

The process of grinding the concave surface of a single-vision spherical lens.

The focal length of a lens is the distance between the lens's optical center (or principal point) and the image sensor or film when the lens is focused at infinity. In simple terms, it is the...

A small mirror, sometimes plane and sometimes concave, attached to the rotating coil of a galvanometer to cause a spot of light to move along a scale.

A telescope with an ellipsoidal secondary concave mirror that reflects rays from a parabolic primary mirror through an opening in the center of the primary, where the image is viewed with an eyepiece.

Laser cavity bounded by a plane mirror and a concave spherical mirror with the plane mirror located at the center of curvature of the concave mirror.

A null optic in the form of a concave spherical mirror; used for the test and evaluation of a hyperboloidal aspheric surface.

A device designed to concentrate and direct a light source by enclosing the source in it and using a concave reflector to direct the light through its only opening.

A metal tool used to grind lenses with loose abrasive (see diamond cutting tool). The functional surface of the lap is carefully formed to be opposite the curve to be produced on the glass (concave...

Laser optics refers to a broad category of optical components and systems designed for manipulating and controlling laser light. Laser optics play a crucial role in shaping the characteristics of...

A lens is a transparent optical device that focuses or diverges light, allowing it to pass through and form an image. Lenses are commonly used in optical systems, such as cameras, telescopes,...

A double-surfaced catadioptric spherical mirror whose spherical first surface consists of a negative meniscus (concave) lens and second rear surface is a spherical mirror. This combination utilizes...

A lens that has one convex surface and the other concave.

A telescope with a concave paraboloidal objective mirror and a small plane (diagonal) mirror that reflects rays from the primary mirror laterally outside the tube where the image is viewed with an...

Also referred to as a funduscope, an ophthalmoscope is a specialized instrument used by ophthalmologists for observing and photographing the fundus (interior) of the eye which includes the retina,...

A permanent, transparent, and highly transmissive adhesive capable of withstanding extreme temperatures that is applied to optical surfaces for the purpose of cementing, or the sticking together of...

A concave mirror that has the form of a paraboloid of revolution. The paraboloidal mirror may have only a portion of a paraboloidal surface through which the axis does not pass, and is known as an...