Jinnan Zhang

Transmission of 112Gb/s PM-RZ-DQPSK over 960 km with adaptive polarization tracking based on power difference

All-optic scheme for polarization multiplexed system de-multiplexing were implemented with high-speed and precise optical polarization tracking based on power difference. Stable polarization demultiplexing with 800rad/s polarization scrambling for 112Gb/s direct detection PM-RZ-DQPSK transmission over 960km was demonstrated.

Mathematic models for a ray tracing method and its applications in wireless optical communications.

This paper presents a new ray tracing method, which contains a whole set of mathematic models, and its validity is verified by simulations. In addition, both theoretical analysis and simulation results show that the computational complexity of the method is much lower than that of previous ones. Therefore, the method can be used to rapidly calculate the impulse response of wireless optical channels for complicated systems.

A novel bidirectional RSOA based WDM-PON with downstream DPSK and upstream re-modulated OOK data

We propose a bidirectional reflective semiconductor optical amplifier (RSOA) based wavelength-division-multiplexing passive optical network (WDM-PON) utilizing a differential phase shift keying (DPSK) signal for down-link and an on-off keying (OOK) signal re-modulated for up-link with high extinction-ratio in both directions. A 20 km range colorless WDM-PON without dispersion compensation was demonstrated within low penalty for both 10 Gbit/s downstream and 5 Gbit/s upstream signals. We investigate the impacts of wavelength and the injection power to the RSOA on upstream data. The BER performances of our scheme show that the performance of our scheme is as good as those in case of continuous wave (CW) light injected RSOA. So our scheme is a practical solution to meet the data rate and cost-efficient of the optical links simultaneously in tomorrows WDM-PON access networks.

Stable 112-Gb/s POLMUX-DQPSK transmission with automatic polarization tracker

The high growth in network bandwidth drives the need to scale DWDM networks and to transport 100GbE signals over existing fiber plants. Polarization-multiplexed return-to-zero differential quadrature phase shift keying (PM-RZ-DQPSK), combined with direct detection and PMD tracker has been considered as a promising solution. In this paper, PM-RZ-DQPSK signals were implemented with high-speed and precise optical polarization compensation. Stable polarization demultiplexing for 800 rad/s polarization scrambling combined with 112 Gb/s direct detection PM-RZ-DQPSK transmission over 960 km was demonstrated.

A high-speed adaptive PMD compensation scheme based on DSP using DPSO algorithm

This paper describes implementation of a DSP for adaptive PMD compensation in 80Gbits/s DQPSK optical fiber communication systems. Using dithering particle swarm optimization (DPSO) algorithm, the searching process and tracking process could be completed in 10ms and 1ms respectively.

An automatic PMD compensation scheme utilizing DPSO algorithm in 80Gbits/s DQPSK system

An implementation of atuomatic PMD compensation in 80Gbits/s DQPSK optical fiber communication systems is demonstrated in this paper. The dithering particle swarm optimization (DPSO) algorithm showed powerful ability of fast searching global optimum without being trapped into sub-optima.

The implementation of a novel electronical compensation scheme for adaptive PMD compensator

The signal impairments producing by Polarization Mode Dispersion (PMD) must be compensated in 40 Gb/s or 100 Gb/s optical fiber communication system. A novel electrically controlled compensation scheme of adaptive compensator for PMD is proposed and realized in this paper. Experimental results show that the proposed compensation scheme can track and compensate the variation of the State of Polarization (SOP) of the optical signal, the response time is only 2.3 µs. 1st-order PMD and 2nd-order PMD compensation experiments have been completed, the PMD compensator can increase the maximal tolerable PMD value by 30 ps and 62 ps in the optical fiber communication system substantially.

Experimental demonstration and analysis of all-optical label swapping based on RZ-DQPSK/IRZ-ASK modulation format

Abstract A novel optical return zero differential quadrature phase shifted keying/inverse return zero amplitude shifted keying (RZ-DQPSK/IRZ-ASK) orthogonal modulation format scheme for all-optical label swapping is analyzed theoretically and experimentally. The transmission characteristics of RZ-DQPSK/IRZ-ASK modulation format transmission system are demonstrated. Results show that high extinction ratio is obtained for IRZ-ASK label signal while at the same time the all-optical label swapping, differential quadrature phase shifted keying (DQPSK) payload signal is hardly affected. It requires only 0.9 dB higher power penalty compared to 21.4 Gbit/s RZ-DQPSK modulation format and less than 2 dB transmission penalty after 60 km. The proposed scheme is a practical solution for meeting the data rate and cost-efficiency of the optical links simultaneously in future all-optical label swapping.

Adaptive PMD compensation based on DSP in optical transmission systems

This paper demonstrates a universal digital signal processing (DSP) application for adaptive polarization mode compensation (PMD) compensation in optical transmission systems. It is significant and challenging to establish an effective logic control compensator due to the time-varying and statistical properties of PMD, especially in high-speed optical fiber communication systems. We designed a low power-consume DSP-based integrated control system to complete first-order PMD and second-order PMD compensation. The searching process and the tracking process for automatic PMD compensation could be completed in less than 10ms and 1ms.

High speed polarization monitoring for adaptive PMD compensation in optical communication systems

A high speed polarization monitoring unit for adaptive PMD compensation is designed and implemented. The experiment results show that it saves much polarization monitoring time and makes the PMD compensation work effectively.