Photonics Dictionary

The part of an electrical circuit in which the electrons leave (a cathode-ray tube) or enter (an electrolytic cell) a unit in the circuit.

An electron-beam tube in which the current to an output electrode is regulated by the transverse motion of the tube's electron beam.

The electron beam tube of a television camera that converts an optical image into a pattern of electrostatic charges and then scans the pattern to produce a corresponding electronic signal for...

The storage surface of an electron beam tube that is scanned by an electron beam to generate an output-signal current corresponding to the charge-density pattern stored.

A light-tight box that receives light from an object or scene and focuses it to form an image on a light-sensitive material or a detector. The camera generally contains a lens of variable aperture...

1. The negative electrode of a device in an electrical circuit. 2. The positive electrode of a primary cell or storage battery. 3. The primary source of electrons in an electron tube, serving as the...

Cathode radiant sensitivity refers to the ability of a photocathode to convert incident radiant energy, typically in the form of light, into an electrical signal. Photocathodes are components used in...

The method of disintegrating the substance of the cathode by bombarding it with ions and depositing it on another electrode or electron tube envelope.

Also known as cathode rays. Formerly, this term described a stream of electrons emitted from the cathode of a gas-discharge tube during its bombardment by positive ions. It also describes any stream...

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 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...

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 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 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 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.

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

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.

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

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...

A small xenon-filled tube with metal electrodes fused into the ends. The gas flashes brilliantly when a condenser is discharged through the tube. The duration of the flash is primarily dependent upon...

The use of an applied electrical field to focus a cathode-ray tube's electron beam.

A nonmagnetic instrument utilizing an electrofocus and deflection tube with a photocathode for imaging purposes. The optical image is converted into a photoelectric output at the photocathode and is...

An image intensifier that uses electrostatics to amplify and focus the electronic image.

Also referred to as a bulb. The glass housing that encloses an incandescent source, or the glass or metal housing that encloses an electron tube.

An X-Y electrically addressable series of arrays with individual electron emitters bombarding a phosphor-coated transparent plate. The phosphor is induced into luminescence, similar to traditional...

The freeing of electrons from a filament in an electron tube as the result of the filament being heated by an electric current.

A transformer that is designed to regulate the amount of current that passes through an electron tube's filament.