Light detecting device and optical system including the same

An optical system comprising:

• a light steering apparatus configured to steer light;
• and
• a light detecting device configured to detect the light steered by the light steering apparatus;
• wherein the light detecting device comprises:
• a light input device;
• a plurality of waveguides extending in a first direction from the light input device, being configured to transmit portions of light input to the light input device, and comprising an extending portion that extends in a second direction that is perpendicular to the first direction, respectively;
• a plurality of modulators provided on the plurality of waveguides and configured to modulate phases of the portions of the light transmitted in the plurality of waveguides, respectively, the plurality of modulators respectively comprising a first modulator electrode and a second modulator electrode which are provided on the extending portion;
• at least one graphene layer configured to absorb the portions of the light transmitted in the plurality of waveguides;
• an intermediate layer provided between the at least one graphene layer and each of the plurality of waveguides, the intermediate layer comprising a material having a refractive index that is less than a refractive index of each of the plurality of waveguides and being discontinuous between adjacent waveguides among the plurality of waveguides;
• and
• at least one first electrode and at least one second electrode electrically connected to the at least one graphene layer.