DEVICE FOR MONITORING OPTICAL SIGNAL QUALITY, PARTICULARLY CONCERNED WITH COMPARING AN ANALOG-TYPE RESTORED DATA SIGNAL WITH AN INVERTING AMPLIFIED SIGNAL WITHOUT ANALYZING FRAMES OF AN OPTICAL SIGNAL

摘要

PURPOSE: A device for monitoring an optical signal quality is provided to restore data by converting an optical signal into an electrical signal while synthesizing the restored data signal with an inverting amplified signal to calculate a difference value, and to measure the power for a filtered signal to monitor the quality of the optical signal, thereby simply monitoring the quality regardless of frames of the optical signal. CONSTITUTION: A photodetector(120) converts a received optical signal into an electrical signal. A clock decision recovery unit(140) detects a clock from the electrical signal, and restores data based on the detected clock. A monitoring unit(160) converts an optical signal outputted from a photo amplifier(100) which couples received optical signals into an electrical signal, inverting-amplifies the converted electrical signal, and synthesizes the inverting-amplified signal with the restored signal to filter the synthesized signals, then measures an RF power from the filtered signals.