120 km lightwave transmission experiment at 1 Gbit/s using a new long-wavelength avalanche photodetector

A transmission experiment was performed to study the high-speed potential of a long-distance gigabit lightwave system employing a single-frequency 1.5 ?m laser and a new long wavelength III?V avalanche photodetector. A 120 km length of standard production single mode fibre was used in the test, in which a bit error rate of 2×10?10 was achieved at 1 Gbit/s. This distance is the longest reported to date for rates higher than 500 Mbit/s, and the product of bit rate and distance (120 km Gbit/s) is the highest value achieved for any bit rate. The distance was limited by the 32.3 dB loss of the transmission path together with a total of 5.6 dB in power penalties associated with chirp broadening of the laser line.     

1 Tbit/s (111 Gbit/s/ch X 10 ch) no-guard-interval CO-OFDM transmission over 2100 km DSF

Spectrally efficient (2bit/s/Hz) 1 Tbit/s DWDM transmission of 111 Gbit/s no-guard-interval PDM CO-OFDM signals with 50 GHz spacing over DSF is demonstrated. The record transmission distance of 2100 km was achieved for a 100 Gbit/s-data-rate CO-OFDM system.     

BER performance improvement by forward error correcting code in 5Gbit/s 9000 km EDFA transmission system

Forward error correction (FEC) has been used to improve the bit error rate performance of a 5 Gbit/s 9000 km erbium-doped fibre amplifier (EDFA) transmission line. The results using a 5 Gbit/s prototype optical transmission terminal showed extremely small penalty in BER performance after 9000 km transmission     

Optical transmission of 16 digitised TV channels over 21 km fibre at a bit rate of 1.12 Gbit/s

The letter describes an optical transmission system which carries 16 digitised TV channels over a distance of 21 km without repeater at a bit rate of 1.12 Gbit/s.     

20 Gbit/s long distance transmission using a 270 photon/bit opticalpreamplifier receiver

A 200 km nonrepeatered transmission experiment and a 400 km transmission experiment using three in-line amplifiers are carried out at 20 Gbit/s by using a simple but highly sensitive optical preamplifier receiver based on a 0.98 μm LD-pumped EDFA. High sensitivity of -31.6 dBm (270 photon/bit) at 20 Gbit/s is obtained     

NTT ultra-fast,large-capacity optical transmission at 400 Gbit/s

By combining optical time-division-multiplexing (TDM) and wavelength division-multiplexing (WDM) with a single super-continuum light source NTT Corp. has successfully conducted an ultra-fast, large-capacity optical transmission experiment at 400 Gbit/s (equivalent to sending 100 years of newspapers in a second) over a distance of 100 km. Having already confirmed that the PLL timing extraction circuit and all optical time-division demultiplexer are able to function at 400 Gbit/s and 200 Gbit/s, respectively, NTT plans to continue R&D efforts to develop an optical transmission system exceeding 1 T bit/s.     

Transmission of 16.4-bit/s Capacity Over 2550 km Using PDM QPSK Modulation Format and Coherent Receiver

A record capacity distance product of 41.8 Petabit/s $cdot$km is demonstrated. A total of 164 channels are modulated at 100 Gbit/s with PDM-QPSK format, packed with 2 bit/s/Hz information spectral density and recovered by off-line processing in a coherent receiver after 2550 km distance.      

10 Gbit/s, 138 km uncompensated duobinary transmission overinstalled standard fibre

The first field demonstration using optical duobinary signalling at 10 Gbit/s over installed fibres is reported. Transmission over 138 km of standard fibre is demonstrated without repeaters or dispersion compensation and with a penalty of only 2.5 dB. This technique significantly increases the bit rate distance product without changing any specifications of the existing fibre network. The influence of fibre nonlinearity on system performance is also investigated     

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.     

640 Gbit/s (32×20 Gbit/s) WDM transmission with 0.4(bit/s)/Hz spectral efficiency using short-period dispersion-managedfibre

640 Gbit/s (32 channel×20 Gbit/s) WDM transmission with 0.4 (bit/s)/Hz spectral efficiency is demonstrated using short-period dispersion-managed fibre (Perfect Cable^TM). The average Q-factor was measured to be better than 18 dB after transmission over 280 km     

1.7 Gbit/s transmission over 165 km of dispersion-shifted fibreusing spectrum-sliced fibre amplifier light source

The authors have demonstrated 1.7 Gbit/s transmission over 165 km of dispersion-shifted fibre using a spectrum-sliced fibre amplifier light source. To the authors' knowledge, this represents the largest bit-rate distance product (280 Gbit/s km) ever demonstrated using an incoherent light source. The dispersion penalty was very small (~0.3 dB) even at a wavelength 10 nm away from the dispersion-zero wavelength of the fibre     

Transmission of 622 Mbit/s spectrum-sliced WDM channel over 60 kmof nondispersion-shifted fibre at 1550 nm

The transmission of a spectrum-sliced WDM channel at 622 Mbit/s over 60 km of nondispersion-shifted fibre using an optical bandwidth of only 0.23 nm is reported. This is the highest single channel bit rate-length product (40 Gbit/s·km) and smallest channel bandwidth reported to date for spectrum-sliced WDM systems. The bit error rate performance is theoretically predicted and experimentally confirmed and limits on the bit rate-length products of spectrum-sliced WDM channels using nondispersion-shifted fibre in the 1550 nm window are given     

2.5 Gbit/s transmission of spectrum-sliced fibre amplifier lightsource channels over 200 km of dispersion-shifted fibre

Transmission of 2.5 Gbit/s spectrum-sliced fibre amplifier light source channels over 200 km of dispersion-shifted fibre (DSF) has been achieved, the highest bit-rate distance product 500 Gbit/s km using incoherent light sources reported to our knowledge. The total power penalty was as low as 0.2 dB for the 1.8 nm bandwidth channel centred at the zero-dispersion wavelength of DSF     

1 Gbit/s transmission experiment over 101 km of single-mode fibre using a 1.55 ?m ridge guide C3 laser

Using a cleaved-coupled-cavity (C3) ridge guide laser which oscillates in a single longitudinal mode at 1.55 ?m wavelength, we report the first lightwave transmission experiment exploying single-frequency lasers at speeds above 500 Mbit/s. We have achieved digital transmission with a bit-error rate of 2 × 10?10 at 1.0 Gbit/s over 101 km of single-mode fibre. This represents a record for the length of unrepeatered optical transmission for bit rates greater than 500 Mbit/s. Evidence for an error-rate floor, presumably due to residual partition noise, is observed. No such floor was observed in an 84 km?1 Gbit/s experiment using the same C3 laser.     

Power penalty analysis due to polarisation diversity on 1.2 Gbit/s optical DPSK heterodyne transmission

An optical DPSK transmission experiment was performed over 100 km at a bit rate of 1.2 Gbit/s using a dual-balanced polarisation-diversity receiver. A high receiver sensitivity of less than -42.8 dBm was achieved and the power penalty due to polarisation diversity was analysed.<>     

2×10 Gbit/s WDM 1310-nm optical transmission over 63.5-kmstandard single-mode fiber using optical preamplifiers

Twenty Gbit/s transmission over 63.5 km SMF at 1310 nm is reported by using two channel 10 Gbit/s wavelength (de)multiplexing (Δλ=1.5 nm). Two 1310 nm SL-MQW semiconductor optical amplifiers are utilized for loss compensation and sensitivity improvement. For the 1310 nm wavelength domain, a record bitrate x distance product of 1.27 Tbit/s.km has been obtained. Crosstalk penalties are identified, and the feasibility of an extension up to at least four, 10 Gbit/s channels is discussed     

10 Gbit/s, 1200 km error-free soliton data transmission using erbium-doped fibre amplifiers

Soliton data signals at 10 Gbit/s have been successfully transmitted for the first time through a 1200 km dispersion-shifted fibre by using 24 erbium-doped fibre amplifiers. A bit error rate below 10/sup -13/ was obtained with 2/sup 20/-1 pseudorandom patterns.<>     

10 Gbit/s optical soliton transmission over 7200 km by using amonolithically integrated MQW-DFB-LD/MQW-EA modulator light source

The authors demonstrate 10 Gbit/s optical soliton transmission in a recirculating loop through the use of a monolithically integrated MQW-DFB-LD/MQW-EA modulator light source. The timing jitter due to the Gordon-Haus effect is successfully reduced by the optical bandpass filters conventionally used in the cascaded EDFAs to avoid the accumulation of amplified spontaneous emission. The transmission distance of 7200 km is achieved at a bit error rate of 10^-9     

Research on the transmission performance of turbo codes in DDO-OFDM system

With the rapid development of optical elements with large capacity and high speed,the network architecture is of great importance in determing the performance of wavelength division multiplexing passive optical network(WDM-PON).This paper proposes a switching structure based on the tunable wavelength converter(TWC)and the arrayed-waveguide grating(AWG)for WDM-PON,in order to provide the function of opitcal virtual private network(OVPN).Using the tunable wavelength converter technology,this switch structure is designed and works between the optical line terminal(OLT)and optical network units(ONUs)in the WDM-PON system.Moreover,the wavelength assignment of upstream/downstream can be realized and direct communication between ONUs is also allowed by privite wavelength channel.Simulation results show that the proposed TWC and AWG based switching structure is able to achieve OVPN function and to gain better performances in terms of bite error rate(BER)and time delay.     

宽带E波段无线传输系统

本实验采用74 GHz本振源与一对矩形喇叭天线实现了非归零开关键控(NRZ-OOK)信号在室内环境下的传输。在实验中还研究了不同传输距离和速率对系统性能的影响。结果表明误码率性能随着距离和速率的增加而下降,使用前向纠错编码(FEC)的5 Gbit/s和6 Gbit/s信号可以在3.6 m内实现无误码传输,而7 Gbit/s信号只能在2.4 m内实现无误码传输。