Methods used in Optical Switches
From MEMS to Acousto-Optics.
Micro-electromechanical Systems (MEMS)
Involves the use of micro-mirrors.
The micro-mirrors are used to deflect optical signals and so that the signal will reach the corresponding receiver thus resulting in switching.
Inkjet methods
Involves the use of two waveguides.
When an inkjet-like bubble is created the optical waveguides deflect the light and pass it to each other.
Liquid crystals
The liquid crystals are used to rotate polarized light that passes through it.
The rotation of the polarized light depends on the electric field used.
Thermal methods
Involves the use of an interferometer.
Heat is applied to one of the legs of the interferometer so that its index of refraction will change making the circuit go on or off.
Non-linear methods
Involves the manipulation of a material’s non-linear properties to change its diffraction pattern and thus be able to deflect light and act as a switch.
Amplifiers/Attenuators
Involves the use of amplifiers and attenuators placed in optical fibers to change the required digital signal to act as switch.
Acousto-optic methods
Involves the application of an acoustic field to change the refractive index of a material and thus be able to deflect light and act as a switch.