Optical amplification constitutes a key component of optical telecommunication.The gain and noise figure of the model operational amplifier are analyzed systematically by optimizing and testing the algorithm model of semiconductor optical amplifier.The results show that the optimal conditions for amplitude modulation or phase modulation is the bias current of 100 mA and input power of -5 dBm or -20 dBm,respectively.The 20km bidirectional transmission communication system with a communication rate of 2.5 Gb/s is analyzed and built,the bidirectional and unidirectional transmission of upstream and downstream for optical network unit integrated with semiconductor optical amplifier and distributed feedback laser is tested.When forward bit error rate is 2.4×10 -4,the sensitivities reach -22.4 dBm and -31.4 dBm for bidirectional upstream and downstream,and the sensitivities reach -23.4 dBm and -23.8 dBm for unidirectional upstream and downstream,respectively.