Photodiodes are semiconductor – based optoelectronic devices that convert light signals to electrical ones via the photoelectric effect. When light hits their PN – junction, electron – hole pairs are created. These separate under the PN – junction’s built – in electric field, forming a photocurrent. Usually operating in reverse – bias, they’re more sensitive and responsive to light.
They’re key for light detection. In comms, they turn fiber – optic light signals into data – carrying electrical signals. In devices, they adjust screen brightness by sensing ambient light. For optical power measurement, they’re used in experiments and industry to gauge light power accurately. In position and displacement detection, they work with components like code disks in encoders for precise position and movement measurement. Also, in spectral analysis, photodiode arrays help analyze light spectra for chemical, biological, and astronomical research.