Serial-parallel combined all optical sequence matching system using highly nonlinear fibers for photonic firewall

Abstract Photonic firewall which can directly conduct intrusion detection and security protection in optical layer is an important network security device. The core part of photonic firewall is all optical sequence matching system. It is responsible for recognizing the target sequence in the input data sequence. In a real environment, the length of the target sequence is not fixed and may be dynamic changing. However, most of existing optical sequence matching systems can only handle the target sequence with a fixed maximum matching length. When the length of a target sequence exceeds the given maximum length, the performance of the system will deteriorate and even the system stops working. How to utilize the existing all optical sequence matching system with a fixed maximum matching length to handle the target sequence with a longer length becomes an important research focus. Moreover, the existing all optical sequence matching systems using all optical logic gates can only handle the optical signal with the modulation format of on-off keying (OOK). In this paper, we design a serial-parallel combined all optical sequence matching system using highly nonlinear fibers (HNLF). It can recognize the target sequence with the length of k times more than the existing all optical sequence matching system. Moreover, this system supports handling the optical signal with the modulation format of binary phase shift keying (BPSK). The simulation platform is constructed by the software of VPItransmissionMaker. Simulation results show that the serial-parallel combined all optical sequence matching can recognize target sequences with the length of 8bits and the modulation format of BPSK at 100 Gbps and 200 Gbps.