Describe the function of a modulator in an opto-electronic system.

The function of a modulator in an opto-electronic system is crucial as it serves to alter the light signal's amplitude, frequency, or phase specifically for communication purposes. In optical communication systems, modulators are used to encode information onto a light signal by varying its properties. This enables the transmission of data over long distances by controlling how the light signal represents information.

For instance, by changing the amplitude of the light, the modulator can represent binary data where high intensity may correspond to a binary "1" and low intensity to a binary "0." Similarly, frequency modulation can be used in applications where different frequencies can represent different channels of information. Phase modulation involves changing the phase of the light wave to convey information, providing another layer of modulation that can enhance data transmission capabilities.

This capacity to manipulate light signals is essential for efficient and effective data transmission in modern communication systems, distinguishing it as a fundamental function of a modulator in opto-electronic applications.