Gigaopto provides PON access networks with a series of SFP-packing PON OLT optical transceiver modules that support GEPON data rates at 1.25Gbps downstream and 1.25Gbps upstream. It is fully compliant with IEEE 802.3ah-2004. The transmitter section uses a 1490nm DFB laser and an integrated laser driver which is designed to be Class 1 eye safety per IEC825 and CDRH standards. The laser driver includes APC and temperature compensation functions, which are used for keeping the launch optical power and extinction ratio constant over temperature and aging. The receiver has a hermetically packaged APD-TIA (trans-impedance amplifier) pre-amplifier and a limiting amplifier with LVPECL compatible differential outputs.The Receiver Loss of Signal (Rx_LOS), Transmit Disable (Tx_DIS), Transmit Fault (Tx_FAULT) and the monitor and control functions are LVTTL compatible. The digital diagnostic monitoring function is fully compliant with SFP MSA.