Photonics Dictionary: I

An atom that has gained or lost one or more electrons and, as a result, carries a negative or positive charge.

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,...

Two oppositely charged particles.

A technique for improving the structure density of thin-film coatings by bombarding the growing film with accelerated ions of oxygen and argon. The kinetic energy then dissipates in the film, causing...

Ion-beam sputtering (IBS) is a physical vapor deposition (PVD) technique used for depositing thin films onto substrates. It involves bombarding a target material with a beam of energetic ions,...

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...

A closed vessel with electrodes of different potentials that is used to determine how much ionization took place in a gas after its exposure to x-rays or radioactive emissions.

The amount of energy required for a particular kind of atom to remove an electron to infinite distance. The ionization potential is usually expressed in volts.

Generally, any radiation that can form ions, either directly or indirectly, while traveling through a substance.

An electroradiographic process that uses ionization of air by x-rays as a basis for forming electrostatic images.

The gas of charged particles that begins approximately 50 km above the surface of the Earth and contains a sufficient quantity of electrons and ions to affect the propagation of radio waves.

The rainbow exhibition of colors, usually caused by interference of light of different wavelengths reflected from superficial layers in the surface of a material.

1. Lines of the same color. 2. A term used in photoelastic stress analysis to refer to the interference fringes produced in birefringent materials.

A graphic depiction of the loci of all points in space relative to a laser transmitter at a specific altitude.

The slight difference in wavelength of an element's given spectral line observed in comparing different isotopes of that element.

That property of a material that determines that velocity of propagation within the material is the same for all directions.