All-Optical Logic AND Gate Based On SOA And Its Application Of Header Extraction

All-optical logic is the key component of all-optical signal process, which can be used in the applications of all-optical tags extraction, all-optical demultiplexer and optical address recognition. Semiconductor optical amplifier (SOA) is very fit for all-optical logic operation due to its non-linear characteristics, lower switch power and small size.The signal processing speed of all-optical logic, which based on SOA-XGM or SOA-XPM, is mainly limited by the carrier recover time of SOA. With the aid of external optical injection, an all-optical logic AND gate based on SOA-MZI scheme is proposed. On the input signal of 20 ps pulse width and 200 ps repeat period, its performance is discussed in detail. At the same time, optical pulse with different repeat period and different pulse width entering into the all-optical logic gate is simulated. As a result, the external optical injection can effectively enhance the signal processing speed of SOA. And the performance of the scheme can be improved by adjusting the powers of the external optical and two input optical.A structure of transmitted packet is proposed. Based on this structure, the packet can be easily extracted the header information, and is suitable for transmitting in all-optical switching network. By using the all-optical logic AND gate which proposed in this paper, a scheme of header extraction is presented. The numerical simulation is given with the transmission rate at 2.5Gbit/s and 5Gbit/s. As a result, it can successfully extract the packet header when the transmission rate is 5 Gbit/s or less. And by using higher performance logic AND gate or optic switch, it can be suitable for packets of higher transmission rate.