APPARATUS FOR DETECTING LOSS OF SIGNAL IN OPTICAL PRE-AMPLIFIER OF TRANSMISSION SYSTEM

摘要

PURPOSE: An apparatus for detecting loss of signal in a transmission system is provided which precisely detects loss of signal, blocks a pump diode from being damaged and prevents the transmission system from abnormally operating. CONSTITUTION: In an apparatus for detecting loss of signal in a transmission system, an optical signal branch unit(100) branches an optical signal received through an optical path into two according to a predetermined ratio. A signal loss detector(110) receives one of the branched signals to check if an optical signal exists therein and generates a shutdown signal when the signal is lost. A pump diode(130) blocks pump light with bias current applied from an output controller when received the shutdown signal from the signal loss detector. An optical signal amplifier(140) receives the other branched signal with the optical signal received from the pump diode to amplify it.