Novel Synchronous Time-domain Spectral Phase Encoding/Decoding Scheme for Secured Optical Communication

摘要

Rapid reconfiguration of optical codes (OCs) can significantly enhance the confidentiality of coherent optical code division multiple access (OCDMA) system [1]. However, most of conventional OCDMA encoding/decoding schemes do not have this capability. Recently, a fast reconfigurable time domain spectral phase encoding (SPE) scheme, which has this capability, has been proposed using high speed phase modulator and arrayed waveguide grating (AWG) decoder [2]. In this paper, we propose a novel synchronous time-domain spectral phase encoding/decoding (SPED) scheme for secured optical communication. Figure 1 shows the schematic diagram of the proposed scheme. The pulse generator generates short optical pulses at data-rate, the SPE consists of a pair of dispersive components with opposite dispersion values (+D and -D) to stretch/compress the optical pulse and a phase modulator (PM) or a hybrid intensity/phase modulator (IM/PM) for data and OC modulation. The spectral phase decoding (SPD) is similar to the SPE with a PM synchronously driven by OC (the complementary pattern of OC) at a repetition rate equal to the data-rate. The OCs thus can be rapidly reconfigured even bit-by-bit to enhance the system confidentiality.