An optical selector includes: an optical waveguide which includes a first light guide section having a first refractive index, a second light guide section having a second refractive index provided to the side of and along the entire circumference of the first light guide section, and a reflector provided at opposing positions on both surfaces of each of the first and second light guide sections while exposing the outer circumferential surface of the second light guide section; a single or plurality of LDs that are placed on the outer circumference of the optical waveguide, and emit light toward the first light guide section; and a single or plurality of photodetectors that are placed on the outer circumference of the optical waveguide, and receive light emitted from the outer circumference of the optical waveguide.