The effect of intra-channel four-wave mixing on the performance of a 160 Gb/s OTDM RZ 100 km transmission system is analyzed. Strong dispersion management to suppress the detrimental effects of intra-channel four-wave mixing is presented theoretically and verified experimentally. Results demonstrate that amplitude fluctuation and ghost pulses are well suppressed by strong dispersion management. Stable (>2 h) error-free (10 −12 ) transmission over 100 km is achieved without forward-error correction, and the power penalty is ~3.6 dB.optical time-division multiplexing, intra-channel four-wave mixing, strong management, error-free
Citation:Jia N, Li T J, Zhong K P, et al. Suppression intra-channel four-wave mixing by strong dispersion management in 160 Gb/s OTDM RZ 100 km transmission. Chinese Sci Bull, 2011Bull, , 56: 2744Bull, −2747Bull, , doi: 10.1007 The demands for huge-capacity transmission have increased with the continuous growth of telecommunication services. Optical time-division multiplexing (OTDM) systems may be viable solutions to these demands. For instance, using OTDM differential quadrature phase-shift keying and polarization multiplexing, signal generation up to 5.1 Tbit/s and error-free demodulation employing direct detection [1] and 1.28 Tbit/s single-polarisation OTDM-OOK (on-off keying) data generation and demultiplexing have been demonstrated [2]. For these high-speed serial data signals, dispersion management is essential for long-haul optical transmission. In a dispersion-managed system, expansion of the transmissible distance is limited by intra-channel nonlinear interactions, which consist of intra-channel cross-phase modulation (IXPM) and intra-channel four-wave mixing (IFWM) [3,4]. IXPM shifts the mean frequency and leads to timing jitter, whereas IFWM brings about amplitude fluctuation via energy transfer and generation of ghost pulses in the zero bit slots, resulting in severe limitations to bandwidth efficiency. The chirped return-to-zero (RZ) pulses are less influenced by IXPM in strongly dispersion-managed lines because the input pulse broadens rapidly and the peak amplitudes become small in spite of the extremely large overlap [4,5]. Therefore, IFWM is the main obstacle for long-distance high-speed transmission. Although IFWM can be reduced using special fibers with low nonlinearity and an ultra-low average dispersion slope [6], it is more cost effective to design the dispersion map than to install new fiber or to modify the transmitter and receiver subsystems when installed systems are upgraded to higher per-channel data rates. Numerical studies have been carried out to understand how to reduce the impact of the amplitude fluctuation and ghost pulse generation induced by IFWM. However, the simulation bit rate has been 40 or 80 Gb/s, which is much [3][4][5][6][7][8][9][10]. Therefore, it is useful to experimentally study and verify strong dispersion management in the case of a 160 Gb/s OTDM RZ transmission system. In this paper, we theoretically analyze the IFWM process and propo...