Electronic Science and Technology
Security Comparison of ± π/2 and 0 / π Phase-shifted Superstructured Fiber Bragg Grating Encoding
Zhang Xuedia
Abstract
In this paper,0 / π-phase-shifted SSFBG( 0 / π-SSFBG) and the ± π /2-phase-shifter SSFBG( ± π/2-SSFBG) are used to encode the optical pulse signal. A comparison is made of the security performance of the 0 / π-SSFBG and the ± π /2-SSFBG. We evaluate the security performance by the investigation of the encoded waveforms of both encoders. The existence of dips in the waveform encoded by 0 / π-SSFBG allows eavesdroppers to extract code sequence straightforwardly. Nevertheless,the ± π /2 SSFBG based encoder improves the security by concealing the code information in the encoded waveform.