Disclosed herein is a single wavelength bi-directional optical transceiver for transmitting/receiving optical signals having the same wavelength through an optical communication system. The optical transceiver includes a transmitter including an isolator and converting an external input signal into an optical transmit signal, an optical filter reflecting some of the optical transmit signal and transmitting the other of the optical transmit signal, an optical fiber transmitting the optical transmit signal transmitted by the optical filter to a counterpart optical transceiver, a receiver receiving an optical receive signal from the counterpart optical transceiver via the optical fiber, and a body enclosing a portion of the transmitter, the optical filter, a portion of the optical fiber and a portion of the receiver. An incidence angle (θ2) formed between a central axis of the transmitter and a central axis of the optical fiber is adjusted to allow the optical transmit signal to be obliquely incident into the optical fiber in order to reduce reflection of the optical transmit signal by the optical fiber without coupling with the optical fiber when the transmitter transmits the optical transmit signal to the optical fiber.