Optical branching equipment and optical network using the same

摘要

In optical branching equipment (441) which is supplied with an optical signal of a first wavelength band from a trunk line terminal equipment via a trunk line cable (300) and is inserted in the trunk line (301), the optical signal is normally provided to the trunk line cable (301) after being bypassed from a branching circuit (OP1) to branch line terminal equipment (401) connected to a branch line cable (611), and when trouble develops in the branch line, the optical signal is delivered to the trunk line cable (301) via a short circuit (OP3). In the short circuit (OP3) there is inserted an optical limiter amplifier (29) which is capable of amplifying light of the first and second wavelength bands. Normally the optical limiter amplifier (29) is saturated by control light (C) of the second wavelength supplied from the branch line terminal equipment (401) via the branch line cable (611), and consequently, the optical signal of the first wavelength band is suppressed. When the supply of the control light (C) is stopped by some cause, the optical limiter amplifier (29) amplifies the optical signal of the wavelength band provided to the short circuit (OP3) and provides the amplified optical signal to the trunk line cable (301).