Acousto-Optical
Acousto-Optical
An acousto-optical material is one for which the refractive index can be changed by the density fluctuations (strain) produced by an acoustic wave.
The change in the dielectric constant, el, is related to the mechanical strain, e, through the photoelastic coefficient, p, such that:
D(1/el )
= pe.
If a longitudinal acoustic wave is sent through an acousto-optically active solid, it establishes a density grating in the material that will diffract a light beam in the manner shown below. The diffracted beam will not be present if there is no acoustic signal (only the transmitted beam will remain) and the device can, therefore, act as an optical switch.
the table shows some parameters of optoacoustic substances.
Source:
1-Freefullpdf for Scientific Publications
2-Solymar and Walsh, "Lectures on the Electrical Properties of Materials," Oxford Science Publications (1988)
1-Freefullpdf for Scientific Publications
2-Solymar and Walsh, "Lectures on the Electrical Properties of Materials," Oxford Science Publications (1988)