Time domain spectral phase encoding/DPSK data modulation using single phase modulator for OCDMA application.

A novel scheme using single phase modulator for simultaneous time domain spectral phase encoding (SPE) signal generation and DPSK data modulation is proposed and experimentally demonstrated. Array- Waveguide-Grating and Variable-Bandwidth-Spectrum-Shaper based devices can be used for decoding the signal directly in spectral domain. The effects of fiber dispersion, light pulse width and timing error on the coding performance have been investigated by simulation and verified in experiment. In the experiment, SPE signal with 8-chip, 20GHz/chip optical code patterns has been generated and modulated with 2.5 Gbps DPSK data using single modulator. Transmission of the 2.5 Gbps data over 34km fiber with BER<10(-9) has been demonstrated successfully. The proposed scheme has simple configuration and improved flexibility that can significantly improve the data confidentiality for optical code division multiple access (OCDMA) and secure optical communication applications.