A METHOD FOR DECREASING AND COMPENSATING THE TRANSMISSION LOSS AT A WAVELENGTH-DIVISION-MULTIPLEXED PASSIVE OPTICAL NETWORK AND AN APPARATUS THEREFOR

摘要

The present invention relates to a wavelength-division multiplexed passive optical network. In particular, it relates to a technology for minimizing the optical loss at a wavelength-division multiplexed passive optical network based on wavelength-locked light source. Thereby it improves the transmission quality and increases the transmission distance. A 4-port optical path setting device of the present invention increases the amount of light injected into an optical transmitter and thereby improves the wavelength-locking characteristic of a light source. In addition, it can decrease the optical transmission loss in an optical transmission path, and by an optical amplifier being inserted therein it can also compensate the optical loss in an optical transmission path. In the present invention, a 4-port optical path setting device having the characteristics described above and a method for fault recovery without an additional optical loss are presented.