... coupled 1550nm /1490nm /1310nm out FTTH,FTTB High-Power Fiber Amplifier,YEDFA FWAP-1550HA Series,PON+CATV EDFA Combiner,32 ... and laser Thermoelectric cooling device Temperature stability control circuit to ensure optimal machine performance and long-life laser stability. ... , micro-processing will automatically turn off laser power, red light goes on to warn, digital panel prompts cause of troubles., ...