Definitions

A camera system in which the image formed on the fluorescent screen of an image converter tube in the system is recorded by photography or direct contact printing from the face of the tube.

In vitro is a Latin term that translates to "in glass." In scientific contexts, particularly in biology and medicine, it refers to experiments or procedures conducted outside of a living organism,...

A lamp that emits light when an electric current passes through a resistant metallic wire situated in a vacuum tube.

An image converter that produces a visible image based on the infrared emittance of the object. The infrared energy is focused on a photocathode that emits electrons. These are accelerated and...

Any of the photoelectric and thermal detectors, spectrographs and monochromators, thermographs, scanners, amplifier tubes, snooperscopes and related equipment developed for use with infrared...

A method that produces low-loss optical fibers. A glass tube rotates while reactants pass through the tube and heat is externally applied by a burner that traverses the tube. The oxidizable vapors in...

An intensified charge-coupled device (ICCD) camera is an advanced imaging device that combines the capabilities of both an image intensifier and a charge-coupled device (CCD) sensor to achieve...

A standard direct-readout vidicon tube linked by fiber optics to an intensifier for increased sensitivity.

The process in which the electron beam of a cathode-ray tube varies in intensity in accordance with the magnitude of the signals it receives.

A laser in which the transition involved in stimulated emission of radiation takes place between two levels of an ionized gas. The gases are electrically excited in a container called a plasma tube,...

Also known as gas focusing. The introduction of an inert gas into a cathode-ray tube for the concentration of the electron beam. The gas molecules are ionized by the electrons, producing a core of...

An instrument designed to measure the index of refraction of a gas by the interference patterns formed by two beams, one of which passes through a vacuum tube in which the gas is slowly released.

1. In relation to cathode-ray tube displays, errors in the signal's amplitude, phase or both that result in small, rapid aberrations in size or position of the image. 2. Errors of synchronization...

A cathode-ray tube that serves as a picture tube in a television receiver. The signal representing the picture intensity is transmitted to the electron gun grid so that the beam intensity varies with...

A thermionic tube that has a velocity-modulated electron stream and that may be used as a microwave amplifier or oscillator.

A term applied to an electric charge image in a camera tube that remains for a period of a few frames after its initial formation.

Laser lithotripsy is a medical procedure that uses laser energy to break down or fragment stones in various parts of the body, particularly in the urinary and biliary systems. The term "lithotripsy"...

The device, usually made of glass or a similar material, that contains the resonant cavity and optics of a gas laser.

The variation of the electronically detected signal with respect to the scaled version of the classical optical signal incident on the photomultiplier tube.

A Laurent polarimeter is an instrument used in optics for measuring the rotation of plane-polarized light caused by optically active substances. Optical rotation, also known as optical activity, is a...

An electron-beam tube designed so that the beam can be carried through a portion of the wall of an evacuated enclosure.

The metal tube that maintains the optical components of a lens in proper relationship. Some lenses are mounted in metal cells, which in turn are screwed to the front and rear of a shutter or lens...

The pattern, formed by a character generation cathode-ray tube system, in which the characters are made up of wave shapes synthesized by a series of sine and cosine terms.

In fiber optic cable, containment of the fiber or fibers within an outer protective tube in which they can move to some extent. The interstices usually are filled with an insulating material. See...

A vacuum tube in which a magnetic field is superimposed onto the tube's electrical field. When the two fields are aligned, electrons from the photocathode are accelerated through the tube in a spiral...

A device using the Kerr effect to read back the signals from mechanically recorded tapes and discs. It consists of a light source, optical lenses to focus and direct the light beam, a pair of...

1. A framelike structure that serves to restrict the viewing area of the screen when placed before a television picture tube. 2. In photolithography, a photomask (or mask) is typically a patterned...

With respect to television, that part of a color television circuit that combines the I, Q and Y signals, and changes them into single red, green and blue signals applied to the picture-tube grids.

A gauge designed to measure high degrees of vacuum. It consists of a glass bulb attached to the vacuum vessel, the measurement being made by filling the bulb with mercury and observing the volume of...

In a microscope, the physical distance between the focal points of the objective lens and the eyepiece. The standard tube length for a microscope is typically 160 mm).

An electric arc that is formed in mercury vapor through which an electric current flows. The intensity of the illumination of the arc depends mostly on its design and the conditions under which it...

A lamp that has mercury in a tube or bulb that has first been evacuated. The electricity travels through the vapor between the electrodes and produces a blue-green light that is rich in ultraviolet...

A microchannel plate (MCP) is a specialized electron multiplier device used in various applications such as particle detection, imaging, spectroscopy, and night vision technology. It consists of a...

An instrument consisting essentially of a tube 160 mm long, with an objective lens at the distant end and an eyepiece at the near end. The objective forms a real aerial image of the object in the...

An eyepiece located at the near end of the microscope tube. It often is a simple Huygens eyepiece, but compensating and flat-field projection eyepieces are quite efficient. Negative eyepieces are...

The lens located at the object end of a microscope tube. A wide range of objectives is available, including simple achromats, the color-corrected apochromats and the flat-field objectives. Objectives...

A device designed to detect microwave modulation and to mix modulated and unmodulated laser beams. It consists of a photosensitive cathode and a microwave-electron-tube structure that amplifies,...

Minimum object distance, often abbreviated as MOD, refers to the closest distance at which a camera lens or optical system is capable of producing a sharp and focused image. In photography, this term...

A type of tubing used to protect optical fiber cables, consisting of a wire spiral of aluminum, galvanized steel or stainless steel, encased in a polyvinyl chloride or silicon rubber coating. These...

A character generation CRT that functions on the principle of secondary emission. The target holds a set of aluminum characters, select characters being scanned by the electron beam. The secondary...

A nanotube, also known as a nanotubule or simply a tube-like structure, is a nanoscale cylindrical structure composed of various materials, including carbon, boron nitride, or other compounds....

In a cold-cathode tube, the luminance between the cathode dark space and the Faraday dark space. In a vacuum tube, the luminance between the Crookes dark space and the Faraday dark space.

A cold-cathode tube containing neon and designed to visually determine a potential difference or field.

An electron tube containing neon gas that uses the transmission of an electric current through the gas to ionize the neon and produce a luminous red discharge.

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...

A device that uses low-level visible radiation or infrared radiation to produce a visual image of a night scene. These devices may rely on the amplification of existing visible light by...

An electro-optical infrared tracker consisting of a beamsplitter, an illuminating source, an image dissector tube and an electronics unit, that automatically acquires and tracks particular eye...

A glow discharge tube placed on an insulating rod to detect the presence of high-frequency radiation in the vicinity of a transmitter. The tube indicates the presence of the radiation by the glow...

A television camera tube in which a low-velocity electron beam scans a photoactive mosaic that has been created by an optical image. Once scanned by the electron beam, the electrical storage capacity...