Time Division Multiplexing Transmission System Research Articles

25-GHz dual-wavelength pedestal-free pulse source based on single-driven dual-parallel Mach-Zehnder modulator and Mamyshev reshaper

A dual-wavelength optical Gaussian pulse generation scheme based on a single-driven dual-parallel Mach-Zehnder modulator with subsequent Mamyshev reshaping is proposed. Experimental results show that nearly chirp-free Gaussian pulses with a full width at half maximum of 2.7-ps and a repetition rate of 25-GHz on 2 wavelengths are achieved simultaneously. By changing the central wavelengths of the continuous wave light and the optical bandpass filter, nearly transform-limited optical Gaussian pulses are obtained over the C-band. The pulse source is further employed in a 100-Gbit/s on–off keying optical time division multiplexing transmission system. Error-free bit error rate performance is also achieved, which confirms the high pulse quality.

An all-optical bit-error indicating scheme based on self-phase modulation and filtering

In this paper, a novel all-optical bit-error indicating scheme is numerically studied. The bit-error indicating function is achieved by two all-optical processing stages. Firstly, the amplified original bit stream propagates through a high-nonlinear fiber and experiences self-phase modulation which causes intensity-dependent spectrum broadening and split. And then, the bit stream output from the high-nonlinear fiber is filtered by a band-pass filter with the same central wavelength as the original bit stream to generate an error bit indicating signal. The error bit indicating signal, in which only the “Error” bits have the highest peak power, is synchronous with the delayed original bit stream. Therefore, the position of the “Error” bits in the original bit stream can be identified by setting only one judge threshold in the error bit indicating signal. The scheme is demonstrated for an 80 Gb/s bit stream with return-to-zero format by simulation. The results show that the scheme can be used for the all-optical bit-error indicating of the super high bit-rate systems using the return-to-zero format which is favored in the optical time division multiplexing transmission systems.

Dynamic PMD compensation in 4×10Gb/s optical time-division multiplexed transmission system

Using the degree of polarization as feedback signal to detect the polarization m ode dispersion (PMD) variation in the fiber links, an experiment of dynamic adap tive PMD compensation in 4×10?Gb/s optical time-division multiplexed (OTDM) tr ansmission system is reported. The PMD compensator consists of a polarization co ntroller and a variable delay line with four degrees of freedom. Based on the va riable step-size peek search algorithm, the performance of the PMD compensator i s assessed in the eye pattern of a received signal. It is shown that the maximum compensated differential group delay is 25?ps, i.e. one bit period, and the co mpensation time can be less than 50?ms.

Bit error rate analysis of an all-optical buffer employed in a soliton based optical time division multiplexed transmission system

In this paper, we compare the theoretical and simulated bit error rate (BER) performance of an all-optical active recirculating fibre loop buffer (RFLB) employed at the transmitter node of an optical time division multiplexed based (OTDM) system, for several buffer storage times (delays). To the best of our knowledge, we believe that this is the first time a theoretical model detailing BER performance based on the delay storage time has been presented in the literature. Moreover, the theoretical model is extended to forecast the power penalties incurred when the delay approaches the millisecond time scale. Thereafter, simulation results are used to compare the power penalty when the RFLB is employed at a receiver node within an optical network scenario. In this work, soliton profiled OTDM packets transmitted at a maximum aggregate data rate of 20 Gbit/s are used as test signals. The buffering architecture consists of a dispersion-shifted fibre (DSF) loop and a switching mechanism. The analysis presented here is intended to promote the understanding of the performance hindering mechanisms within a RFLB architecture and may prove invaluable to future optical buffer designers.

Impact of fiber chromatic dispersion in high-speed TDM transmission systems

General guidelines for high-speed time-division multiplexing (TDM) data-rate transmission are essential for the increase of the overall transmission capacity. In this paper, general theoretical investigations concerning fiber chromatic dispersion in optical TDM systems are performed. Recent experiments that confirm the theoretical predictions are presented. Nonzero dispersion-shifted fiber and standard single-mode fiber are recommended for 40 and 160 Gb/s, respectively, independent of the chromatic dispersion compensation scheme.

Interferometric noise in optical time division multiplexing transmission system

A theoretical assessment of the interferometric noise in the optical time division multiplexing (OTDM) transmission system is presented. The impact of such noise on the system performance were investigated in detail. The corresponding system requirements were also revealed by the calculation results. Recommendations on the use of prechirping to reduce the interferometric noise in the OTDM system are given.

Ultrahigh-bit-rate optical transmission research in Japan

Recent progress toward ultrahigh-bit-rate optical fibre transmission systems employing optical time-division multiplexing (TDM) techniques is reviewed. Focus is placed on 100 Gbit s$^{-1}$ optical TDM transmission systems and the related technologies studied in Japan. Successful 100 Gbit s$^{-1}$ TDM transmission experiments over 200-500 km and the key technologies are described, including ultrashort optical pulse generation, all-optical multiplexing-demultiplexing and optical timing extraction techniques, together with state-of-the-art performances and future prospects.

20 Gbit/s, 205 km optical time division multiplexed transmission system

A 20 Gbit/s optical time division multiplexed transmission system based on components and subsystems operating at not more than 5 GHz repetition rate is reported. Full BER measurements indicate a penalty of only 0.8 dB after transmission through 205 km of dispersion-shifted fibre. The penalty was mostly attributed to the accumulation of noise from erbium-doped fibre repeater amplifiers in the system.

Optical time-division multiplexed transmission system experiment at 8 Gbit/s

We describe the design and performance of an experimental two-channel optical time-division multiplexed fibre transmission system operating at a wavelength of 1.3 μm and a bit rate of 8 Gbit/s. Transmission over 8 km of single-mode fibre with low crosstalk and transmission error rates as low as 10 -10 is demonstrated.

16 Gbit/s fibre transmission experiment using optical time-division multiplexing

An experimental four-channel optical time-division multiplexed transmission system is described, and the first demonstration of fibre transmission at a bit rate of 16Gbit/s is reported. In this experiment, data at 16Gbit/s have been transmitted over 8 km of fibre with a bit error rate below 10-9.