Double-pass resonant Er-Raman amplifier

A new double-pass wideband Er-Raman fibre amplifier is proposed, pumped by a Raman laser oscillating through a medium consisting of Er-doped fibre and dispersion compensating fibre in series.     

80 Gbit/s pulsewidth-maintained wavelength conversion based on HNLDSF-NOLM including transmission over 80 km of conventional SMF

80 Gbit/s pulsewidth-maintained wavelength conversion based on a high-nonlinearity dispersion shifted fibre nonlinear optical loop mirror (DSF-NOLM) is realised and penalty-free transmission over 80 km conventional single mode fibre and 12 km dispersion compensating fibre of the converted signal is demonstrated for the first time     

Analysis of wideband dispersion slope compensating optical fibresby supermode theory

The behaviour of a dispersion compensating fibre is expressed by three simple parameters based on the supermode theory and compared to measurements. Dispersion and dispersion slope can be described by these parameters, regardless of the profile     

Picosecond pulse generation of <5 ps from gain-switched DFBsemiconductor laser diode using linearly step-chirped fibre grating

4.4 ps pulses generated from a 1546 nm gain-switched DFB-SLD using a 6 mm long linearly step-chirped fibre grating represent a temporal compression factor of 4.3. The pulse source is stable. Compact and dispenses with the dispersion compensating fibre conventionally used for pulse compression     

Dual concentric core dispersion compensating fibre optimised for WDM application

A dual concentric core fibre exhibiting a chromatic dispersion coefficient around -350 ps/(nm km) is used in a dispersion compensating module designed for WDM application. The optimised length ratio is larger than 20 and the residual chromatic dispersion is measured at 0.4 ps/(nm km) in the C-band     

Generation of 6.3 ps optical pulses at a 10 GHz repetition rateusing a packaged electroabsorption modulator and dispersion compensatingfibre

Sinusoidal modulation of an MQW InGaAsP/InGaAsP EA modulator at a 10 GHz repetition rate was used to generate optical pulses of width as low as 7 ps. Pulses were linearly compressed using 400 m of dispersion compensating fibre and approximately transform limited pulses of 6.3 ps width were measured     

Broadband high-gain dispersion compensating Raman amplifier

A Raman gain module compensating for both loss and dispersion of a 40 km standard telecommunication fibre span over the 1510-1565 nm band is reported. The optimised configuration ensures a low signal-spontaneous noise figure and negligible double-Rayleigh scattering noise. The high-gain margin of the amplifier makes it applicable for compensation of an 80 km span     

一种新型的基于LP01模的双模色散补偿光纤

通过计算机模拟发现在可传输双模的三包层色散补偿光纤中如果抑制ＬＰ０２模，而仅传输ＬＰ０１模时能在一个较窄的带宽内产生大于数千ｐｓ／ｎｍ·ｋｍ的负色散，并且具有较大的模场直径、较小的弯曲损耗和偏振模色散，另外还具有较小的温度波长漂移以及同其它色散补偿光纤一样大小的损耗，是一种非常有前途的新型色散补偿光纤     

A novel multi-waveband dispersion compensating fiber based on hybrid photonic crystal fiber

In view of dispersion compensating in multiple wavebands at the same time, this paper proposes a novel multi-waveband dispersion compensating fiber (DCF) based on hybrid photonic crystal fiber (PCF). The proposed fiber can compensate multiple wavebands at the same time. The mechanism of the multi-waveband dispersion compensation is analyzed, and the different material-filled structure is discussed numerically. The simulation results show that the multi-waveband DCF can compensate multiple wavelengths at the same time. By a reasonable design, this fiber can replace the multi-dispersion compensating system composed by cascaded multiple devices, and minimize the loads of the system in an efficient way.     

Dispersion slope equaliser using bend-induced positive dispersionslope in coiled pure-silica fibre

The dispersion slope of a dispersion-shifted fibre has been successfully equalised by using a bend-induced positive dispersion slope in a singlemode fibre. We realised the bent fibre dispersion slope equaliser by using a 1.3 μm zero-dispersion pure silica core fibre (PSM). This equaliser provides a dispersion slope of -12.54 ps/nm² /km in the 1.5 μm region     

Compensation of fibre chromatic dispersion in optical heterodynedetection

Compensation of fibre chromatic dispersion in coherent optical fibre transmission is demonstrated. The chromatic dispersion of a 70 km single-mode fibre with 1.3 μm zero dispersion wavelength is compensated for using a microstrip line equaliser in the intermediate frequency band. Amplitude distortion due to fibre chromatic dispersion at 1.55 μm wave-length is reduced to below 2.5 % with the equaliser     

低阈值短腔随机分布反馈光纤激光器

设计了一种低阈值短腔随机分布反馈光纤激光器,采用1455 nm的激光二极管泵浦一段色散补偿光纤,采用正向反馈和反向反馈两种结构分别将一阶随机激光阈值降至760 mW和520 mW,且反向反馈结构的二阶阈值与一阶阈值相同,分析了色散补偿光纤长度对阈值的影响,实验证明优化色散补偿光纤长度是降低一阶与二阶随机激光阈值的有效方法。     

Design and characterization of dispersion compensating fiber basedon the LP01 mode

The practical implementation of erbium-doped fiber amplifiers with gain at 1.55 μm allows long unrepeatered transmission distances. However, in order to realize high data rates over these distances with already installed standard single mode fiber, techniques must be found to overcome the pulse spreading due to the positive chromatic dispersion of the transmission fiber in this window, we review a compensation technique based on propagating the signals through a specially designed fiber with large negative dispersion for the LP₀₁ mode, thereby ending up with zero net pulse spreading. The basis of the concept are discussed and a key figure of merit for dispersion compensating devices is defined. The design and optimization of dispersion compensating (DC) fiber is described with special attention to practical concerns including packaging and manufacturability. We describe experimental fabrication results of DC fiber, results of using the fiber to make compact dispersion compensating modules, and the outcome of recent systems experiments incorporating the fiber     

光子晶体光纤在光通信中的色散补偿应用

通过合理设计可使光子晶体光纤具有较大的负色散,利用这一特性可以制作新型光纤器件,用于现代光纤通信系统的色散补偿,这可大大缩短色散补偿光纤的长度。阐述光子晶体光纤在现代宽带光通信系统的色散补偿技术中的应用潜力,并说明如何设计光子晶体光纤的几何结构来补偿目前商用光通信系统中传输光纤的色散。     

Measurement of fibre-optic chromatic dispersion from RIN spectra of a tunable fibre laser

The chromatic dispersion of optical fibre is determined from the wavelength dependence of the mode spacing of the fibre laser with and without the intracavity test fibre. This approach is particularly useful for characterising the dispersion of modelocked fibre lasers, where control of the total laser dispersion is required.<>     

Chromatic dispersion measurement over a 120 km dispersion-shifted single-mode fibre in the 1.5 ?m wavelength region

Chromatic dispersion in the 1.47?1.60 ?m wavelength region is measured successfully for a dispersion-shifted fibre over 120 km by the LD phase-shift method. The measured value of a 123 km spliced fibre agrees well with the sum of chromatic dispersion values of its constituent fibres. This confirms the additive rule of chromatic dispersion for long dispersion shifted fibre in the 1.5 ?m wavelength region.     

Change of field spectrum of signal light due to fibre nonlinearities and chromatic dispersion in long-haul coherent systems using in-line optical amplifiers

The change of a field spectrum of signal light in long-haul coherent optical fibre communication systems using in-line amplifiers is measured in the normal and anomalous dispersion regions of a fibre. Results show that the interplay of nonlinear Kerr effect and fibre chromatic dispersion cause a fatal change in the field spectrum in the anomalous dispersion region.<>     

Wavelength dispersion in a single-mode fibre

Wavelength dispersion in a single-mode fibre has been evaluated by measuring propagation times of various-wavelength pulses transmitted through a 3.72 km-length fibre. Dispersion in a single-mode fibre is dominated by material dispersion, and is estimated to be 9.1 ps/? dkm at 0.85 ?m wavelength.     

Experimental demonstration of step-like dispersion profiling inoptical fibre for soliton pulse generation and compression

Generation of 100 GHz trains of 500-700 fs pulses using dual-frequency beat conversion in a step-like dispersion profiled fibre is reported. The authors believe that this is the first time the generation and compression of soliton pulses using such a fibre has been demonstrated. The fabrication of such fibre assemblies does not require any special facilities and relies only on conventional optical fibre technology. They believe that the use of profiling the fibre dispersion by fibre segments instead of continuously dispersion-decreasing fibre is not only possible but preferable in many applications     

Multiple stage dispersion compensation in long haul optical fibresystems using chirped fibre Bragg gratings

Modelling is used to assess the performance of an optical fibre link which has fibre grating dispersion compensators spaced at intervals along its length. A 10 Gbit/s electroabsorption modulator with high positive chirp is shown to transmit in excess of 158 km in normal dispersion fibre using two 2 cm long compensators, incurring a dispersion penalty of only 1.0 dB. Thus the transmission range is improved by a factor of 6.6 over the uncompensated case