TWO-WAY OPTICAL TRANSMISSION SYSTEM

摘要

PROBLEM TO BE SOLVED: To reduce or avoid the interference of optical beams by providing the peculiar combination of a transmitter and a receiver at an access point in the network of a two directional light transmission system using auxiliary carrier multiplexing. SOLUTION: Lasers 301 and 307 at two different positions along one optical fiber 350 generate transmission signals by two different optical spectra. The optical spectral characteristics of the two transmitters are selected so that an optical carrier during the operation of the system has an optical frequency having a difference exceeding a maximum frequency which is clearly used as a sub-carrier. Even if the wavelength of the transmitter changes based on the stimulation of a temperature and the like, it is necessary to select the sufficiently different wavelength so that the possibility of the overlap of the wavelengths does not exist at all. Thus, two-way transmission can be realized in sub-carrier multiplexing environment under such a condition.