In opto-electronics, what purpose does a photodetector serve?

A photodetector is a crucial component in opto-electronics as it serves the primary function of converting light into an electrical signal. When light photons strike the photodetector, they can excite electrons, allowing a measurement of the light intensity based on the resulting electrical response. This conversion is essential for various applications, including sensors, communication systems, and imaging devices, where light needs to be detected and processed in its electrical form for further analysis or action.

The other options do not accurately describe the main purpose of a photodetector. Amplifying light signals pertains more to devices that increase the strength of light signals rather than converting them, while storing light energy is not a function of photodetectors, as they primarily respond to incident light rather than hold energy. Regulating the wavelength of emitted light is related to modulation devices or filters, which alter the characteristics of light rather than detecting it.