Photonics Dictionary: E

Scattering caused by the interaction between ingoing and outgoing particles of the same type, with no loss of kinetic energy.

A refracting telescope that uses a prism to bend the line of sight 90°.

The use of a krypton laser system for the measurement of small molecules aligned by an electric field, by analyzing the absorption of linearly polarized light.

A lamp that uses the transmission of an electric current through a gas or vapor to produce illumination. Neon, mercury and argon lamps are examples of electric-discharge lamps.

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

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...

The nonthermal conversion of electrical energy into light in a liquid or solid substance. The photon emission resulting from electron-hole recombination in a PN junction is one example. This is the...

The utilization of the light produced when electrical energy is directly converted into light within devices used for visual readout displays or as complex logic-circuit elements. With EL lighting,...

A panel of photoconductive and electroluminescent layers used as either a positive or negative image intensifier, depending on amplitude and phase of its two power supply voltages. The...

A type of modulation spectroscopy that measures spectral reflectance or transmittance changes induced by applying a perturbing electric field. It can be performed in contactless modes with no special...

A device utilizing an electron beam for the observation and recording of submicroscopic samples with the aid of photographic emulsions or other short-wavelength sensors. With the electron microscope,...

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

The theory and interpretation of spectra produced by the electron emissions of substances after their irradiation by x-rays.

An instrument that serves to produce an enlarged electron image on a fluorescent screen by focusing an infrared image of a distant object upon a photosensitive cathode.

The method by which photographic film is scanned by an electron beam. One technique uses the uniform light of a television screen, focused by a lens onto the processed film, as a means of creating a...

A method that uses electronic means to move the scanning spot along the scanning line.

A type of electromodulation that measures changes in spectral reflectance.

A type of electron microscope in which the specimen also serves as the cathode source.

A study of the energies and wavelengths of radiation emitted by atoms and molecules when particular physical conditions are applied to them.

An endoscope is a medical device used for visualizing and examining the interior of hollow organs, body cavities, or confined spaces within the body. It consists of a flexible or rigid tube equipped...

The photographing of objects within generally inaccessible areas using endoscopes with camera attachments.

A device for projecting either opaque matter or transparent slides onto a screen.

Fluorescence imaging technique in which the excitation light from the objective is directed into the sample producing emission at all angles. Light emitted into the objective is measured allowing the...

A telescope that is mounted on an equatorial mount.

A high-frequency approach to the propagation of light in graded-index fibers in which the modal field is represented in terms of an inhomogeneous (evanescent) plane wave with a complex phase, so that...

A lens mounting with eccentric rings that may be rotated to shift the axis of the lens to a prescribed position.

In image processing, the location of edges by employing templates that respond to the first or second derivative of gray-scale intensity in the neighborhood of each pixel.

An edge-emitting light-emitting diode is a type of LED structure where light emission occurs primarily along the edge of the semiconductor chip rather than from the surface. Edge-emitting LEDs are...

For a lens with an obscured or noncircular aperture, the focal length divided by the effective aperture.

1. That portion of the aperture that functions to collect energy and deliver it to the final system detector. 2. For an obscured or noncircular aperture, the equivalent nonobscured, circular aperture.

A scale attached to a microscope eyepiece that is seen superimposed on the image and that is used to measure the dimensions of the viewed object.

A device that uses four electrodes set in an alternating positive-negative polarity series to focus the beams of charged particles employed in electron microscopes and particle accelerators.

An electro-optic deflector is a device that can change the direction of light beams using an electric field. It operates based on the electro-optic effect, which involves the modulation of the...

An electro-optic modulator (EOM) is a device used to modulate the amplitude, phase, or polarization of light waves using an external electrical signal. Electro-optic modulation is a fundamental...

Conduction of an electric current through a chemical compound in its natural state, solution or as a molten, to decompose the compound.

Radiation emitted from vibrating charged particles. A combination of oscillating electrical and magnetic fields that propagates through otherwise empty space with the velocity of light. This constant...