Photonics Dictionary: M

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...