Page 249 - Electrical Engineering Dictionary

media where the index change is linearly re- electroacoustics science of interfacing
lated to applied field; the quadratic electro- between acoustical waves and corresponding
optic coefficient describes media where the electricalsignals. Thisincludestheengineer-
index change is related to the square of the ing of transducers (e.g., loudspeakers and mi-
applied field, i.e., the Kerr effect. crophones), but also parts of the psychology
of hearing, following the notion that it is not
electro-optic device any device that uses necessary to present to the ear signal compo-
the electro-optic effect, such as for optical nents that cannot be perceived.
beam modulation and deflection.
electrocardiography (ECG) the device
electro-optic effect an optical phenome- (electrocardiograph) or the output (elec-
non in certain types of crystals in which the trocardiogram) depicting the body surface
application of an applied electric field results recording of the electrical activity of the
heart.
in a change in the dielectric tensor, or equiv-
alently a change in the refractive index of
electroencephalography (EEG) record-
the medium. In the linear electro-optic ef-
ings of the electrical potentials produced by
fect, the resulting change in refractive index
the brain.
is proportional to the electric field strength; in
the quadratic electro-optic effect, the result-
electroluminescence a general term for
ing change in refractive index is proportional
optical emission resulting from the passage
to the square of the electric field strength.
of electric current.
The linear electric-optic effect was first stud-
ied by F. Pockels in 1893.
electrolyte current-conducting solution
between two electrodes or plates of a capac-
electro-optic modulator a device that
itor, at least one of which is covered by a
uses the electro-optic effect to alter the tem-
dielectric.
poral and spatial character of a light beam.
electrolytic capacitor a capacitor solu-
electro-optic scanner a device that uses
tion between two electrodes or plates of a
the electro-optic effect to scan a light beam
capacitor, at least one of which is covered by
across a range of angles.
a dielectric.
electro-optic smart materials materials electromagnet a magnet that employs an
in which optical properties are changed self- electric current in a coil to produce a mag-
adaptively with an external electric stimulus netic field.
proportional to the sensed optical character-
istics. electromagnetic compatibility (EMC)
the ability of a system or equipment to
electro-optic switch a device that uses the operate within design tolerances in its in-
electro-optic effect to switch a light beam on tended environment, with adjacent systems
or off. and equipment, and with itself, so that the
effect of any electromagnetic disturbances
electro-optic wave retarder a device that produced by the systems or equipment is re-
will retard the phase of an optical beam by a duced.
fixed amount using the electro-optic effect;
in particular, the retardation of one polariza- electromagnetic energy energy con-
tion component of the light beam using the tained in electromagnetic fields and associ-
electro-optic effect in a birefringent material. ated polarizable and magnetizable media.

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