Light receiving device

A light receiving device comprising:

• a first waveguide unit provided in a first region of a substrate, the first waveguide unit being configured to propagate a plurality of first lights;
• a second waveguide unit provided in a second region of the substrate, the second waveguide unit being configured to receive the plurality of first lights and generate a plurality of second lights on the basis of the plurality of first lights;
• a third waveguide unit provided in a third region of the substrate, the third waveguide unit including a plurality of waveguides configured to propagate the plurality of second lights;
• and
• a photo-detector unit provided in a fourth region of the substrate, the photodetector unit including a plurality of light receiving elements configured to receive the plurality of second lights from the plurality of waveguides,
• wherein each of the plurality of waveguides includes
• a core configured to propagate a corresponding one of the plurality of second lights, and
• wherein each of the plurality of light receiving elements includes:
• a first semiconductor layer having a first conductivity type, the first semiconductor layer being configured to receive a corresponding one of the plurality of second lights from a corresponding one of the plurality of cores along a first direction, the corresponding core extending in the first direction,
• an absorbing layer configured to absorb the corresponding second light received by the first semiconductor layer, and
• a second semiconductor layer having a second conductivity type opposite to the first conductivity type.