The working principle of modulators varies based on their type but generally involves the interaction between an input signal and a control signal. For instance:
In electro-optic modulators, an electric field is applied to a material with a variable refractive index, thus modulating the light passing through it. In plasmonic modulators, the interaction between light and free electrons on a metal surface is controlled to modulate the signal. In quantum dot modulators, quantum dots change their optical properties in response to external stimuli, modulating the signal accordingly.
