Photonics Dictionary: E

Uniform measure of time based on dynamics law and calculated according to planetary orbital paths; specifically, Earth's orbit about the sun.

The length of time during which the receiver is irradiated.

A characterization of the throughput performance of data storage systems; the EDR is the total of data retrieved divided by the total time it takes to retrieve it, expressed as megabytes per second.

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...

The photographic recording of images produced by the electrons from an electron microscope. The electron beam carries the images through an array of three lenses, and an enlarged electron image is...

An EMCCD (electron-multiplying charge-coupled device) camera is a type of scientific camera specifically designed for low-light imaging applications that require high sensitivity and fast readout...

A method of thin-film deposition in which electrons boiled off a heated cathode are used to melt the coating material. If a multipocket crucible is used, many materials can be processed at the same...

An electron-beam lithography (EBL) system is a sophisticated nanofabrication tool used in the semiconductor industry and research laboratories to pattern extremely fine features with sub-micrometer...

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...

A mechanical shutter that has had its timing escapement replaced with an electronic timing circuit. This circuit allows a wider range of exposure times, can be more accurate, and, placed in a circuit...

A term applied to the recording of video images by means of magnetic tape or disc, so that the image's record can be played back in a video format at a later time.

Embedded vision refers to the integration of computer vision technologies into various embedded systems, devices, or machines. Computer vision involves teaching machines to interpret and understand...

The emissivity of a body times the emissive power of a blackbody at the same temperature. For a blackbody, it is the total radiation per unit area of radiating surface.

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 entrance slit, also known simply as the slit, is an essential component in optical instruments such as spectrometers and monochromators. It is a narrow opening or aperture through which light...

Epitaxial equipment refers to a set of specialized tools and systems used in the process of epitaxy, which is the growth of crystalline layers on a substrate material. Epitaxial growth is a critical...

A stimulus that contains equal energy at each wavelength in the visible region of the spectrum.

The condition in a multimode optical waveguide in which the relative power distribution among the propagating modes is independent of length.

An Er:YAG laser is a type of solid-state laser that uses a crystal made of erbium-doped yttrium aluminum garnet (Er:Y3Al5O12) as the gain medium. The erbium (Er) ions are introduced into the crystal...

Etaloning is an optical phenomenon that occurs in imaging systems, particularly in devices such as spectrometers, interferometers, and cameras. It is characterized by the appearance of interference...

A sensor generally used for infrared imaging. It consists of two chambers separated by a thin, blackened membrane. An infrared image is formed on the membrane by a lens or mirror and produces...

An event-based image sensor, also known as a dynamic vision sensor (DVS), is a type of digital imaging device designed to capture visual information in a highly efficient and unique way compared to...

1. The process by which an atom acquires energy sufficient to raise it to a quantum state higher than its ground state. 2. More specifically with respect to lasers, the process by which the material...

The amount of energy required to raise the energy level of an atom; a necessity if the atom is to radiate energy. High excitation potential is the amount of energy in the upper state of the...

An exciton is a quasiparticle that represents the bound state of an electron and a hole in a solid-state material, typically a semiconductor or an insulator. In simpler terms, an exciton is a paired...

In optics, the total radiant energy incident on a surface-per-unit area. It is equal to the integral over time of the radiant flux density. Also known as radiant exposure.

An instrument used to measure the light from a scene to be photographed and to indicate the camera lens and shutter settings required to expose the film correctly. The exposure time required in a...