An optical transceiver system includes a transmitter transmitting out a first light beam with a first wavelength, a receiver receiving a second light beam with a second wavelength; an optical fiber transmitting the first light beam and the second light beam; and a light guide member. The light guide member includes a lens block having a first side surface facing toward both the transmitter and the receiver, and a second side surface facing toward the optical fiber. A first lens portion and a second lens portion formed on the first side surface for optically coupling the respective transmitter and receiver, a third lens portion formed on the second side surface for optically coupling the optical fiber, and a wavelength divisional multiplexer embedded in the lens block. The wavelength divisional multiplexer receives and divides the first light beam and the second light beam.