Photonics Dictionary: C

A surface that envelops a bundle of rays or bundle of normals to the wave surface. It may be observed as a hollow, luminous cusp in a turbid medium.

In a laser, the optical resonator formed by two coaxial mirrors, one totally and one partially reflective, positioned so that laser oscillations occur.

A CCD camera, or charge-coupled device camera, is a type of digital camera that utilizes a CCD image sensor to capture and record images. CCD cameras are widely used in various applications,...

A CCD image sensor, or charge-coupled device image sensor, is a type of electronic device used to convert optical images into electronic signals. It is a key component in digital cameras, camcorders,...

An adaptation by Philips and Sony of their audio compact disc technology for optical disc data storage and retrieval. Current capacity of a disc is 0.5 to 0.6 gigabytes of information.

A technical specification for a consumer product drawn up by Sony and Philips. CD/I combines audio, video and text recorded as interleaved channels on a disc similar to an audio compact disc. The...

1. A single unit in a device for changing radiant energy to electrical energy or for controlling current flow in a circuit. 2. A single unit in a device whose resistance varies with radiant energy....

An adhesive used for bonding optical elements or for holding devices.

The surface of an element of a compound lens that will produce the cemented interface. The curves of this interface are called inside curves. To facilitate cementing, the two inside curves should...

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.

That viewpoint at which the angular subtenses of points in the picture are identical to angular subtenses of the original points in the scene, at the camera lens.

In an interferogram, an intense portion of the recording that corresponds in size to the amount of infrared radiation incident on the detector.

The surface curvature designed to reduce the marginal error found in the periphery of a spectacle lens.

A lens system in which the centers of curvature of all surfaces fall on a common axis.

1. Mounting a lens or mirror so that its optical axis is coincident with the optical or mechanical axes of other portions of the system. 2. The machining (edging) of the outside diameter of a lens...

In the SI system, prefix meaning one hundredth, 10-2.

In a reflecting telescope, the obstruction of the primary mirror by a secondary mirror which blocks a small amount of the light reflected by the primary mirror and introduces additional diffraction.

The computer module whose circuitry interprets instructions and guides the actions of the peripherals. Also known as the mainframe.

In a perfectly centered lens, the mechanical axis (defined by the ground outside the diameter of the lens) is made to be exactly coincident with the optical axis (defined by a line through the...

A rotating chamber that can be spun at different speeds to generate great radial forces used to simulate different gravity loads.

A microscope that can be used to observe and magnify microscope specimens while they are being centrifuged. The objective rotates near the periphery of the centrifuge head, and the ocular is...

An instrument that detects high-energy charged particles by analysis of the Cerenkov radiation that they emit.

The radiation produced when a charged particle traverses a medium that has a refractive index considerably greater than unity. The moving particle has a velocity that exceeds the velocity of light in...

A polishing material that has a quicker polishing action than rouge (ferric oxide) and that is cleaner to handle.

An isotope of cesium that emits negative beta particles and has a half-life of 2.19 years; its applications include photoelectric cells and developmental ion propulsion systems.

Colorless crystals used in photoelectric cells and for photosensitive material in cathodes.

A photoemissive detector sensitive to wavelengths up to 1 µm. It has one sharp maximum of sensitivity at 350 nm and a broad maximum at 800 nm.

A phototube having a cesium-coated cathode that has its greatest sensitivity in the infrared region.

A lamp that emits light as the result of the passage of an electrical current through ionized cesium vapor.

A photocathode that exhibits maximum sensitivity in the blue and ultraviolet regions of the spectrum. The sensitivity is obtained by the exposure of a thin layer of antimony to cesium vapor at an...