Photonics Dictionary

A high-quality, narrow-angle lens of high aperture designed for low magnification in the recording of cathode-ray tube images.

The luminous trace formed on the cathode-ray tube screen by the motion of the electron beam.

A vacuum tube with an electron gun at one end and a fluorescent screen at the other. Electrons emitted from a heated filament are accelerated by a series of annular anodes at progressively higher...

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

Proprietary name for a low-light-level TV pickup tube.

A photoelectric detector consisting of a glass tube internally coated with a low conductance material. Voltage applied along the tube causes photoemission from the photocathode at the end of the tube...

A cathode-ray tube that generates symbols for use in other displays. The tube operates by scanning specific characters on the target and generating them as video signals to other cathode-ray systems.

In the optical field, a tube to which a lens is fastened for centering.

1. A device used in chemistry to compare the colors of solutions held in flat-bottomed tubes and viewed along the length of the tube. Often a solid glass plunger is moved along one of the tubes to...

1. In optics, the bending of light rays toward each other, as by a convex or positive lens. 2. Turning in the eyes to view a near object. 3. In a television picture tube, the crossing of the...

A glow-discharge tube in which the discharge takes place in the conical or crater-shaped depression at one end of the tube.

A diode with a semiconducting material, such as germanium or silicon, for one electrode, and a fine wire "whisker'' which lies on the semiconductor, as the other electrode. The low capacitance...

The portion of a glow discharge tube that permits little or no light transmission.

An accurate cathode-ray tube display used to provide visual representation stored in a computer for the interpretation and evaluation of the data.

The circuit that regulates an electron beam's deflection in a cathode-ray tube.

The progressive defocusing of a cathode-ray tube display image that occurs when the deflected electron beam impinges on the cathode-ray tube screen at a slant.

A metal coil or coils wrapped around the outside of the neck of a cathode-ray tube. Current passing through the coils produces a magnetic field, which can be used as an alternative to deflection...

A detector array refers to a collection of individual detector elements arranged in a two-dimensional grid or matrix format. Each element within the array is capable of detecting electromagnetic...

A flanged or plain ring with a restricted aperture, located in an optical system at any of several points, that cuts off marginal light rays not essential to image formation. Diaphragms are used as...

A two-electrode device with an anode and a cathode that passes current in only one direction. It may be designed as an electron tube or as a semiconductor device.

The observation of a reproduced television picture on the face of a cathode-ray tube.

A cathode-ray tube in which secondary emission electrons form a display of high intensity.

The observable illustration of an image, scene or data on a screen such as a console or cathode-ray tube, seen as a graph, report or drawing.

A cathode-ray tube that either splits an electron beam from one source or uses beams from two sources to produce two beams, each of which can produce separate traces, but which can overlap.

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.

A device that detects radiation by utilizing the influence of light in forming an electrical signal. It may be a phototube; a photoconductive, photovoltaic or photojunction cell; a phototransistor;...

The spectroscopic analysis of interference patterns using an electronic imaging tube with a Fabry-Perot interferometer to record the fringes.

Type of solid-state display tube in which the readout surface is coated with a material that changes color when positively or negatively charged.

A device consisting of an airtight quartz tube that holds the material to be analyzed. When a high-frequency electrostatic field, generated by microwaves, is applied to the tube, it emits energy of a...

An image intensifier tube that uses a magnetic field for focusing. It yields high-quality images, but its use is limited by its size and weight relative to other image tubes.

An electron lens consisting of a homogeneous axial electric field and a magnetic field used in high-quality image tubes for high modulation transfer function and small geometrical distortion...

In a cathode tube, the electrode that serves as a source for electrons.

A cathode-ray tube that increases the brightness or size of an image or forms a visible image from invisible radiation. The focal plane for the optical image is a large, light-sensitive, cold...

An electron-beam tube with power-handling capability that is essentially based on controlled electron beams. Its control and screen grids are basically in alignment.

The deflection of a beam of electrons, at regular intervals, across a cathode-ray tube screen, according to a definite pattern.

1. A device generally used in a cathode-ray or camera tube to emit a stream of electrons moving at uniform velocity in a straight line. It consists of an emitting cathode and an anode, with an...

The recording of the information contained in a modulated electron beam onto photographic or silicon resin-coated materials. A direct recording method involves the passage of the recording medium...

An electron-gun system is an assembly used to generate and control a focused beam of electrons. Electron guns find applications in various fields, including cathode ray tubes (CRTs), electron...