Fibre transmission of 10 Gbit/s signals following wavelengthconversion using a travelling-wave semiconductor optical amplifier

The wavelength of an intensity-modulated signal at 10 Gbit/s was translated from 1546 to 1531 nm using cross gain-compression in a semiconductor optical amplifier. The shifted signal was transmitted with less than 1 dB penalty over a 121 km span of dispersion-shifted fibre with two in-line amplifiers. A dispersion penalty of nearly 2 dB is measured for transmission of 6 Gbit/s data over 20 km conventional fibre     

Compensation of 202 km single-mode fibre chromatic dispersion in 4Gbit/s optical CPFSK transmission experiment

Compensation for fibre chromatic dispersion in a coherent transmission system is demonstrated. A 4 Gbit/s optical CPFSK signal at 1.55 μm is transmitted through a 202 km conventional single-mode fibre. There is 1.8 dB degradation in transmission caused by fibre chromatic dispersion. This degradation has been completely compensated for using a delay equaliser with optical heterodyne detection     

Application of a Prechirp Technique to 10-Gb/s Transmission at 1064 nm Through 24 km of Photonic Crystal Fiber

The prechirp effect on 10-Gb/s transmission in the 1000-nm band over photonic crystal fiber (PCF) was investigated both experimentally and theoretically. We performed transmission experiments using a 24-km-long PCF whose optical loss and chromatic dispersion were 0.94 dB/km and$-$20 ps/nm/km at 1064 nm, respectively. We confirmed an improvement in the bit-error-rate performance after the transmission, namely a “negative power penalty” of about$-$0.5 dB. Our experimental result and theoretical estimation revealed that the signal degradation induced by the chromatic dispersion can be effectively suppressed by employing the prechirp technique with a conventional$Z$-cut lithium niobate modulator.     

All-Optical 10 and 40 Gbit/s RZ-to-NRZ Format and Wavelength Conversion Using Semiconductor Optical Amplifiers

We demonstrate that the cross-gain compression (XGC) in a semiconductor optical amplifier can produce effective return to zero (RZ)-to-nonreturn to zero (NRZ) format conversion. This technique is experimentally investigated at 10 and 40 Gbit/s. At 10 Gbit/s, the format adaptation allows for a very high pulsewidth increase, i.e., from 10 to 100 ps. The output 10 Gbit/s NRZ signal is transmitted on metro-like links with no chromatic dispersion compensation.      

160 Gbit/s soliton data transmission over 200 km

Polarisation- and time-domain-multiplexed 160 Gbit/s soliton signals have been successfully transmitted over 200 km for the first time. The soliton source was a 10 GHz regeneratively modelocked fibre laser and a planar lightwave circuit was used for optical multiplexing. The soliton pulse width was ~1.5 ps. A polariser and a nonlinear loop mirror were used for demultiplexing from 160 to 10 Gbit/s     

10 Gbit/s dispersion supported transmission field trial over 123 kmstandard singlemode fibre for HDTV studio interconnection

A bidirectional studio interconnection system operating at 10 Gbit/s over 123 km installed standard singlemode fibre is presented. Uncompressed HDTV programme channels are transmitted in STM-format without an in-line repeater, using the dispersion supported transmission (DST) method     

Ultralow loss and long length photonic crystal fiber

We have succeeded in fabricating a low-loss and long length photonic crystal fiber (PCF) by improvement of fabrication process. The fiber is 10 km long and has a lowest loss of 0.37 dB/km at 1550 nm ever reported. We also succeeded in reducing the OH absorption loss to 3 dB/km. This is almost the half of the value ever reported. Using the low-loss PCF, we performed the first DWDM transmission experiment. DWDM signal of 8/spl times/10 Gbit/s is successfully transmitted through the PCF.     

2.4 Gbit/s 100 km penalty-free conventional fibre transmission experiments using GaInAsP electroabsorption modulator

The superior characteristics of a semiconductor modulator for a multi-Gbit/s and long-haul fibre transmission are confirmed for the first time. A 2.4 Gbit/s over 100 km conventional single-mode fibre transmission has been successfully achieved by using a GaInAsP electroabsorption modulator. No power penalty was observed even under 1700 ps/nm chromatic fibre dispersion.<>     

Tolerance of dispersion-managed soliton transmission to the shapeof the input pulses

We showed that long-distance transmission is affected by the source pulse tails. Fast tail dropoff dramatically improves the transmission. We found that the tails must be at least 20 dB down 50 ps from the peak in order to successfully transmit signals over 20 000 km at 20 Gbit/s with anomalous path average dispersion. While tails that are 15 dB down 50 ps from the peak are sufficient to transmit data at 10 Gbit/s over 20 000 km with anomalous path average dispersion, the tails must be down at least 25 dB 50 ps from the peak to transmit data with slightly normal path average dispersion     

基于SOA啁啾管理的连续可调谐色度色散补偿的研究

提出了一种新型的可小范围连续调谐的色度色散(CD)补偿方案.该CD补偿方案包括一个半导体光放大器(SOA)和一段固定长度的色散补偿光纤(DCF).利用SOA的交叉相位调制(XPM)效应,通过调节SOA的偏置电流和控制脉冲光的强度,可以对进入SOA的光信号引入不同大小的附加啁啾量,从而可以利用固定长度的DCF得到补偿后的无啁啾光信号.实验中,实现了10 Gb/s可调谐CD补偿器,在无需替换DCF的情况下,实现了补偿范围为-40 ps/nm到60 ps/nm的连续可调谐CD补偿.     

Field demonstration of soliton transmission at 10 Gbit/s over 2000km in Tokyo metropolitan optical loop network

Experimental field transmissions of solitons at 10 Gbit/s over 2000 km have been successfully demonstrated using part of the Tokyo metropolitan optical loop network. The network is composed of conventional dispersion-shifted 200 core optical fibre cable which was not originally intended for soliton transmission. However, with the dispersion-allocated soliton transmission technique, an error-free 13 ps soliton data train was successfully transmitted over 2000 km. The power penalty at a BER of 10^-10 was 3.1 dB     

Optical transmission experiment at 1.12 Gbit/s using a graded-index fibre with a length of 1.652 km

The letter describes the transmission of an optical p.c.m. signal with a pulse rate of 1.12 Gbit/s by using a graded-index fibre with a length of 1.652 km and a c.w. semiconductor laser as transmitter. We studied the dependence of the dispersion on the laser wavelength and on the coupling arrangement between laser and fibre. For estimating the material dispersion, we analysed the dynamic spectral behaviour of the laser.     

Flatly broadened supercontinuum generation at 10 Gbit/s using dispersionflattened photonic crystal fibre with small normal dispersion

Supercontinuum generation at 10 Gbit/s using a nonlinear dispersion-flattened photonic crystal fibre is experimentally demonstrated. The fibre has small normal dispersion with a variation smaller than 1.5 ps nm^-1 km^-1 between 1500 and 1650 nm. The supercontinuum with a flatly broadened spectrum of 92 nm (at 6 dB) in the 1.55 mum region is generated by injecting 1545 nm, 1.5 ps optical pulses into an 80 m-long fibre     

1.6 Tbit/s(40×40 Gbit/s)光通信传输系统

在国家自然科学基金网(NSFCNet)上已实现由400 km×10 Gbit/s传输链路直接升级的一路400 km×40 Gbit/s光传输实验的基础上,采用自行研制的40×40 Gbit/s载波抑制归零(CS-RZ)码多波长光发送源,进行了160 km的1.6 Tbit/s(40×40 Gbit/s)波分复用(WDM)光传输实验。实验结果表明,对于常规中短距离10 Gbit/s传输链路可以直接升级至40 Gbit/s。但是由于40 Gbit/s传输系统的色散容限小于60 ps/nm,而且传输光纤与色散补偿模块的色散斜率不匹配,要实现40通道40 Gbit/s的传输,必须对40个信道分别进行精细的色散补偿。这也说明,对于宽带的40 Gbit/s多波长系统,有必要优化设计或更新传输链路。     

100 Gbit/s, 50 km, and nonrepeated optical transmission employing all-optical multi/demultiplexing and PLL timing extraction

A 16*6.3 Gbit/s, time-and-polarisation division multiplexed optical signal is successfully transmitted through a 50 km dispersion shifted singlemode fibre employing all-optical multi/demultiplexing. A 6.3 GHz timing clock is directly extracted from the multiplexed 100 Gbit/s optical signal by a phase locked loop (PLL) using a travelling-wave laser diode amplifier. A wavelength-tunable modelocked Er/sup 3+/-fibre ring laser and a planar-lightwave-circuit time division multiplexer are newly developed for this experiment.<>     

Tunable error-free optical frequency conversion of a 4 ps opticalshort pulse over 25 nm by four-wave mixing in a polarisation-maintainingoptical fibre

Error-free, tunable optical frequency conversion of a transform-limited 4.0 ps optical pulse signal is demonstrated at 6.3 Gbit/s using four-wave mixing in a polarisation-maintaining optical fibre. The process generates 4.0-4.6 ps pulses over a 25 nm range with time-bandwidth products of 0.31-0.43 and conversion power penalties of less than 1.5 dB     

Optical self-homodyne DPSK transmission at 1 and 2 Gbit/s over 86 km of fibre

Optical self-homodyne DPSK transmission has been achieved at 1 and 2 Gbit/s data rates with respective receiver sensitivities of ?34.4 dBm and ?32.4 dBm at 10?9 BER. No dispersion penalty was observed after transmission through 86 km of optical fibre with 17 ps/?m/km dispersion at the operating wavelength of 1.53 ?m.     

40 Gbit/s transmission over photonic crystal fibre using mid-span spectral inversion in highly nonlinear photonic crystal fibre

Transmission at 40 Gbit/s over large mode area photonic crystal fibre (PCF) together with dispersion compensation by optical phase conjugation in a highly nonlinear PCF are demonstrated for the first time.     

10 Gbit/s transmission over air-guiding photonic bandgap fibre at 1550 nm

The first data transmission over air-guiding photonic bandgap (PBG) fibre is demonstrated. A 10 Gbit/s signal was successfully transmitted at 1550 nm over 150 m of singlemode PBG fibre, thus demonstrating their applicability to optical communications. Furthermore, the impact of the polarisation properties of PBG fibres is highlighted experimentally.     

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