Ming Chen

Method of improving bandwidth efficiency for OTDM transmission systems

Spectrum compression based on filters for improving bandwidth efficiency is presented and demonstrated experimentally in 40Gb/s OTDM system. Even after 100km transmission, demultiplexing and clock recovery can be implemented successfully, and the data rate-to-bandwidth ratio has been improved to 4 times.

Clock Recovery and Demultiplexing for 80Gbit/S OTDM System

Demultiplexing for OTDM networks utilizing a pair of concatenated electroabsorption modulators (EAMs) is presented and demonstrated experimentally. 80Gbit/s OTDM signal is demultiplexed to base rates of 20 and 10Gbit/s with the two EAMs, respectively. The two EAMs combined with a 10GHz clock recovery module based on phase-locked loop is introduced to extract the frame clock from 80Gbit/s OTDM signal. Keywords-optical time division multiplexing (OTDM); demultiplexing;clock recovery (CR), electrical absorption modulator(EAM).

Experimental and theory study the system performance of TOAD using for demultiplexing in 160Gb/s OTDM transmission system

The system performance of TOAD are experimentally studied, the non-ideal problems encountered in the experiment are numerical simulated. The results show the opposite direction fibre lengths are no need to be equal while unperfected coupling ratio, signal polarization rotation are crucial limit for the demultiplexing application in 160Gb/s OTDM system.

40Gbps NRZ transmitted over 500km based on broadband dispersion compensation CFBG

Using broadband dispersion compensation CFBGs, over 500km-40Gbps NRZ transmission system on G.652 fiber will be demonstrated without electric regenerator, FEC and Raman amplifier. The power penalty is about 2dB @ BER =10-10.The CFBGs have better performance: 3dB band is about 1.2nm, group delay ripple is less than 25ps near center wavelength, power ripple is less than 2dB, and DGD is less than 1ps. In order to stabilize the DC bias of the LiNbO3 MZ modulator, a semiconductor cooler is applied to control the temperature. The effect is perfect.

160 Gb/s OTDM demultiplexing based on two cascaded electro-absorption sampling windows

One 160 Gb/s optical time division demultiplexer based on two cascaded electro-absorption modulators as sampling windows was demonstrated and experimentally studied in detail. The two stages were used for the 160 Gb/s into 40 Gb/s demultiplexing and 40 Gb/s into 10 Gb/s demultiplexing respectively.

Stable error-free single channel 160-Gb/s OTDM 100-km transmission via high-precision dispersion management

A single channel with a 160-Gb/s optical time-division-multiplexing (OTDM) transmission over 100 km is fabricated. With the help of 500-GHz optical sampling oscilloscopes, the fiber length is adjusted to the order of 10 m, which corresponds to the accuracy of 0.4 ps for the dispersion compensation. The dispersion map is optimized for the 100-km transmission link. A completely error-free transmission with the power penalty of 3.6 dB is achieved for 2 h without using forward error correction.

Demonstration of clock recovery for 80Gb/s OTDM signals

A 10GHz clock extracted from 80Gb/s OTDM signals is demonstrated experimentally based on Stimulated Brillouin scattering. The recovered clock exhibits excellent stability. In addition, the presented clock recovery scheme is easy to extract clock with any or multiple tributary rates, and the 40GHz and full 80GHz clock are subsequently recovered in simulation.

Suppression of stimulated Brillouin scattering with phase modulator in soliton pulse compression

A phase modulator is employed in the scheme of soliton pulse compression with dispersion shifted fiber (DSF). Stimulated Brillouin scattering (SBS) effect, as a negative influence here, can be dramatically suppressed after optical phase modulation. The experimental result shows that the launched power required for high-order soliton pulse compression has been significantly increased by 11 dB under the condition of 100-MHz phase modulation. Accordingly, the experiment of picosecond pulse compression generated from electro-absorption sampling window (EASW) has also been implemented.

Novel scheme of clock recovery for high-speed OTDM signals based on stimulated Brillouin scattering

A new but simply implemented optical clock recovery scheme for optical time-division multiplexing (OTDM) systems based on stimulated Brillouin scattering (SBS) effect is presented and demonstrated experimentally. According to the unequal-amplitude even-multiplexed OTDM signals, the frame clock is extracted. In addition, the clock with multiple tributary rates is recovered from 160-Gb/s OTDM signal in simulation by utilizing the clock recovery module.

Study on the polarization scrambling time for ultra-high-speed optical fiber communication systems

A 160Gbit/s optical time-division-multiplexing (OTDM) transmission system with polarization Scrambler is demonstrated experimentally. The Scrambler based on the structure of the all-fiber dynamic polarization controller (PolaRITE II by General Photonics Co.). The polarization controller is controlled accurately the peak scrambling frequencies and the corresponding half-wave voltages by home-made a singlechip circuit. Both theory and experience show that the rate of scrambler is related to the spectrum width, spectral distribution, modulation rate and so on. The rate of Scramble for broadband light would be much slower compare with narrowband light to carrying out depolarization. In the same width of spectrum, light with abundant spectrum would need a slower rate. The relationship between the Rate of Scrambler and the Character of different Lasers will be discussed by using Stokes parameters and Mueller matrix. And the experiments performed to verify the results of theoretical analysis results. The Scrambler can reduce Intersymbol Interference, Polarization Mode Dispersion (PMD) and Polarization Dependent Loss (PDL) that have are validated experimentally. Based on the Scrambler, the 160-Gb/s OTDM transmissions are successfully demonstrated.