Abstract: A semiconductor light receiving element includes: a substrate; a semiconductor stacked portion that is formed on a first region of the substrate; and a first electrode and a second electrode that are electrically connected to the semiconductor stacked portion. Te semiconductor stacked portion includes: a light absorption layer of a first conductivity type including InxGa1-xAs; and a second region of a second conductivity type other than the first conductivity type that is located on the opposite side to the substrate with respect to the light absorption layer and bonded to the light absorption layer. The first electrode is connected to a first portion of the first conductivity type located on the substrate side with respect to the light absorption layer in the semiconductor stacked portion.

Abstract: A light detection element includes a semiconductor substrate, a light absorbing layer of a first conductivity type formed on the semiconductor substrate, a cap layer of a first conductivity type formed on the light absorbing layer, and a semiconductor region of a second conductivity type formed within the cap layer and forming a pn junction with the cap layer. A depletion layer formed around the semiconductor region does not reach the light absorbing layer in a case where a reverse bias is not applied to the pn junction, and exceeds a position amounting to 50% of a thickness of the light absorbing layer from the cap layer side in a case where a reverse bias of 20 V is applied to the pn junction.

Abstract: A light detection device includes a first photodiode, a second photodiode connected in series to the first photodiode, a first light source configured to output first pulsed light to which the first photodiode is sensitive, and a signal output unit configured to output a current as a detection signal, the current that flow through the second photodiode.

Abstract: A light detection device includes a first photodiode, a second photodiode connected in series to the first photodiode, a first light source configured to output first pulsed light to which the first photodiode is sensitive, and a signal output unit configured to output a current as a detection signal, the current that flow through the second photodiode.

Abstract: A light detection element includes a semiconductor substrate, a light absorbing layer of a first conductivity type formed on the semiconductor substrate, a cap layer of a first conductivity type formed on the light absorbing layer, and a semiconductor region of a second conductivity type formed within the cap layer and forming a pn junction with the cap layer. A depletion layer formed around the semiconductor region does not reach the light absorbing layer in a case where a reverse bias is not applied to the pn junction, and exceeds a position amounting to 50% of a thickness of the light absorbing layer from the cap layer side in a case where a reverse bias of 20 V is applied to the pn junction.