PURPOSE: A bidirectional optical transfer module is provided to control the penetration and reflection of an optical signal of a first wavelength band and a second wavelength band by the slope of an optical filter. CONSTITUTION: An optical transmitter(300) outputs a wavelength-locked optical signal by the optical signal of a second wavelength band that is received through a reflector(500). The reflector reflects the optical signal to an optical filter(200). The optical filter reflects a reflected wavelength-locked optical signal to a stub module(100). The stub module transmits the optical signal through an optical network.
