# An avalanche photodiode is a photodiode designed in such a way that it releases a pulse of electrons per photon instead of just one. When it is reverse-biased above the breakdown voltage, through the process mentioned above, the avalanche photodiode uses the energy from the photon to release photodiode from its metastable state and create a pulse. | # An avalanche photodiode is a photodiode designed in such a way that it releases a pulse of electrons per photon instead of just one. When it is reverse-biased above the breakdown voltage, through the process mentioned above, the avalanche photodiode uses the energy from the photon to release photodiode from its metastable state and create a pulse. |