Abstract: A front-illuminated avalanche photodiode (APD) includes an opening (16) for incident light, a number of various semiconductor layers from the opening and downwards including a multiplication layer (7), a field-control layer (8) and an absorption layer (10), where the absorption layer is arranged to absorb photons. Under the absorption layer (10) there is at least one Bragg mirror (14) arranged to reflect photons, that have passed the absorption layer (10) from the opening back to the absorption layer.