Content deleted Content added
No edit summary |
|||
Line 11:
An electro-optic modulator is a device which can be used for controlling the power, phase or polarization of a laser beam with an electrical control signal. It typically contains one or two Pockels cells, and possibly additional optical elements such as polarizers. The principle of operation is based on the linear electro-optic effect (the Pockels effect, the modification of the refractive index of a nonlinear crystal by an electric field in proportion to the field strength).
The crystal which is covered by electrode may be considered to be a voltage-variable wave-plate. When a voltage is applied, the retardation of laser polarization of the light would be changed while a beam passes through an ADP crystal. This variation in polarization results in intensity modulation downstream from the output polarizer. The output polarizer converts the phase shift into an amplitude modulation. The ideal electro-optic material possesses all of the following properties:
• large change in refractive index per volt.
• high optical quality and transmission
Line 30 ⟶ 32:
----
== Optical modulators using semiconductor nano-structures ==
| |||