Glossary - alphabet order - "E"

EMI noise

This noise is emitted as electric waves from crystal oscillation circuits and peripheral circuits. The higher-frequency components of the oscillation frequency range is the main components of the electric wave interference noise.


Electrodes exist as the metal layers that has been formed on a crystal chip surface in order to drive a crystal chip and produce a drive output. Usually, metals such as gold, silver, or chrome are used due to their anti-corrosive properties, their affinity with crystal materials, and also cost benefits.

Equivalent circuit of crystal unit

Equivalent circuit of crystal unit

An example of an equivalent circuit for a crystal unit is shown at right. In this example, electrical circuits replace the crystal unit's resonance operation mode.

Etalon filter

It is an spectral splitter including two parallel reflection planes that generate multiple interference between them. The amount of filtered light varies like sine curve depending on the wavelength of light. The gradient part of since curve of the filter is used in a diode light source of which wavelength is changed by ambient temperature.

Extraordinary ray

A light ray whose speed depends on its propagation axis in a birefringent crystal. This ray does not follow Snell's law. (See description of ordinary ray.)

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