433 terms
Photonics Dictionary: E
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EDPelectronic data processing
EDRequivalent direct radiation; effective data rate
EDTelectrodeless discharge tube
EDTAethylenediaminetetraacetic acid
EDWAerbium-doped waveguide amplifier
EDXRFenergy-dispersive x-ray fluorescence
EECEuropean Economic Community
EELSelectron-energy-loss spectroscopy
EETexcitation energy transfer
effefficiency
effect filterA color filter, generally used in photography, to emphasize certain color tones and to modify others in a picture for a more dramatic image. A blue effect filter, for example, darkens red and yellow,...
effective f numberFor a lens with an obscured or noncircular aperture, the focal length divided by the effective aperture.
effective aperture1. 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.
effective beamIn photoelectric sensing, the portion of the transmitted beam that actually functions in the system; the diameter of the beam that determines the presence or absence of an object by being blocked or...
effective colorThe color of an object when it is illuminated by a nonisophotic source.
effective data rateA 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.
effective focal length -> focal lengthThe focal length of a lens is the distance between the lens's optical center (or principal point) and the image sensor or film when the lens is focused at infinity. In simple terms, it is the...
effective numerical apertureThe real numerical aperture (NA) of a fiber when the computed NA is not valid because of change in the glass indices during drawing and fusion.
efficiencyAs applied to a device or machine, the ratio of total power input to the usable power output of the device.
EFGedge-defined film-fed growth
EFLeffective focal length; equivalent focal length
EFPelectronic field production
EFPIextrinsic Fabry-Perot interferometer
EFSextrafield sensitivity
EFTAEuropean Free Trade Area
EGAenhanced graphic adapter
EGDelectrogas dynamics
egg-cratingA weight reducing method whereby material from the rear of a reflector is removed leaving a pattern of ribs normal to the surface in an egg-crate pattern.
EGMerbium gain module
EHDelectrohydrodynamics
EHFextremely high frequency
EHPelectron-hole pair
EIexposure index
EIAElectronic Industries Alliance
eikonometerA 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.
EILelectron injection laser
einsteinA unit of energy equal to the amount of energy absorbed by one molecule of material undergoing a photochemical reaction, as determined by the Stark-Einstein law.
Einstein coefficientsThree proportional coefficients labeled Am, Bmn, and Bnm, that respectively characterize the rate of spontaneous emission, induced emission, and absorption of radiation by an atom, ion or molecule.
Einstein shiftA shift in the direction of the red in the spectral lines of light which, defined by the relativity theory, will have decreased frequencies upon emerging from a highly gravitational field.
Elelevation angle
ELelectroluminescent
EL-PCelectroluminescent-photoconductive
elastic scatteringScattering caused by the interaction between ingoing and outgoing particles of the same type, with no loss of kinetic energy.
elasto-optic effectA change in the refractive index of an optical fiber caused by variation in the length of the fiber core in response to mechanical stress.
elastomerAny material of a macromolecular nature that can stretch at room temperature to more than twice its length and return to approximately its original shape when stress is released.
elateriteThe organic inclusion in quartz crystal that forms delicate films and microspheres and that shows a maximum absorption at 450 nm.
elbow telescopeA refracting telescope that uses a prism to bend the line of sight 90°.
ELDelectroluminescent diode
elecelectric
electric arc -> arc dischargeThe electric arc that is a particular discharge between two electrodes in a gas or vapor which is characterized by high cathode densities and a low voltage drop.
Photonics DictionaryE