Chromatic dispersion characteristics of optical fibre submarine cable under deep sea environmental conditions

First chromatic dispersion characteristics of pure silica-core matched cladding single-mode fibre submarine cable under deep sea environmental conditions are presented. It is confirmed that variations of zero-dispersion wavelength and dispersion at 1.55 mu m wavelength of the cable under hydraulic pressure (0-800 atm), tension (0-6 tons) and temperature change (3-30 degrees C) are less than +or-0.6 nm and +or-0.06 ps/km/nm, respectively.<>     

海底光缆规范的最新进展

主要介绍了GB/T 18480-2001<海底光缆规范>更改为"GB/T 7424.6-200X<光缆第6部分:分规范海底光缆>"的研究修订状况.随着时间的推移和技术的不断发展,版本演变更新势在必行.与GB/T 18480-2001相比,本次修订版本在技术内容方面主要差异作一介绍,并进行对比分析,以期使读者对新版有所了解.     

Water propagation blocking properties of submarine optical fibre cable

A submarine optical fibre cable is developed which has excellent water propagation blocking properties. Propagation is estimated to be less than 750 m/month at a depth of 8000 m. It also has low-loss properties of 0.40 dB/km at a wavelength of 1.3 ?m.     

Time evolution of polarisation mode dispersion in 120 km installed optical submarine cable

The timewise evolution of polarisation mode dispersion (PMD) is measured. PMD varies very slowly in 120 km installed optical submarine cable. The measured timewise evolution of PMD suggests that compensation with a response time shorter than a few minutes can greatly reduce the system performance degradation caused by PMD.<>     

Reduction of high surge voltage on coiled optical fibre submarine cable

The induced high surge voltage caused by a sudden change of feed current on the long coiled optical fibre submarine cable has been measured. The reduction methods of the induced voltage have been examined and their effects are demonstrated.     

First field demonstration of optical submarine cable system using LD-pumped Er-doped optical fibre amplifier

The authors report on the first field demonstration of an optical submarine cable system using an in-line Er-doped optical fibre amplifier pumped by a 1.47 mu m laser diode. The experiment was performed at an ocean depth of 3000 m. With a maximum optical repeater gain of 20 dB, 1.2 Gbit/s intensity-modulated optical signals were transmitted stably during and after installation and also during recovery of the system. Furthermore, the effectiveness of an automatic-gain-control (AGC) scheme proposed for optical amplifiers was confirmed in a practical environment.<>     

Design and characteristics of optical fiber unit for submarine cable

An optimum design method is presented for a "spaceless" unit structure in submarine optical fiber cable. The unit structure has been designed taking into consideration the loss increase caused by both a 40-km-long winding unit and a temperature change of 100°C. An appropriate jacket thickness and hardness was found which satisfies these requirements.     

Polarisation fluctuations of optical fibre submarine cable in 6000m deep sea trial

The difference between the polarisation fluctuations of an optical fibre submarine cable during laying and recovery in a 6000 m deep sea trial is discussed. State of polarisation variations in real time (≃ 6 msec) were measured by a Stokes parameter analyser using an LiNbO₃ device. The maximum power spectra of the polarisation fluctuations during cable laying and recovery were less than 50 Hz     

Deep sea trial of 1.55 μm optical fibre submarine cable system

The first 6000 m deep sea trial of a 1.55 μm optical fibre submarine cable system was successfully conducted in the Pacific Ocean, near Torishima Island, in January 1988. By using 1.55 μm loss-minimised single-mode fibre cables and submerged fully monolithic Si-IC regenerators with DFB lasers, excellent transmission performances at 140, 280 and 565 Mbit/s were obtained through 150 km repeater spacings, respectively     

Dynamic polarization fluctuation characteristics of optical fibersubmarine cables under various environmental conditions

Polarization fluctuation characteristics of optical-fiber submarine cable under 8000-m-deep sea environmental conditions, optical-fiber submarine cable coupling under periodic variable tension, and cable performance during and after installation, are presented. As a worst case, it is demonstrated that the maximum frequency spectrum of polarization fluctuation is less than 200 Hz under dynamic composite stress states. It is found that the polarization fluctuation of the optical-fiber submarine cable coupling changes linearly with periodic variable tensile forces. It is confirmed that the power spectrum of polarization fluctuations are less than 50~60 Hz, and the maximum power spectra are between 5 and 10 Hz during the cable installation within a maximum cable tension of 18 kN (1.8 tons) and the cable laying speed of 3.5 knots, respectively     

Characteristics of wire-space-type submarine optical cable

A new type of submarine optical cable, called wire space cable, is proposed for utilisation in shallow sea areas. In the cable, optical fibres are inserted into spaces formed between stranded wires, which are used as tension members. It has been found from a cable pulling test that nonarmoured cable elongation at 8000 m in water depth is 0.3% and armoured cable elongation at 6000 m is 0.5%. Furthermore, a hydraulic pressure test has shown that single-mode-fibre loss at 1.3 ?m wavelength does not increase up to a water depth of 2700 m.     

Polarisation fluctuation in optical-fibre submarine cable under 8000 m deep sea environmental conditions

Polarisation fluctuation in optical-fibre submarine cable under 8000 m deep sea environmental conditions (hydraulic pressure of 80 MPa, tensile force of 50 kN and temperature of 3°C) are presented. It is found that the frequency spectrum of polarisation fluctuation is less than about 2 kHz in dynamic stress conditions.     

Optical loss measurement results on an experimental optical fibre submarine cable of 30 km length

A continuous length of 30 km optical fibre submarine cable was successfully manufactured and laid on the sea bed about 1000 m deep. After the sea trial of 17 months, the cable was recovered from the sea bed. No significant degradation was observed in the optical loss of the recovered cable.     

Degree of polarisation in a birefringent single-mode optical fibre

We examine the evolution of the polarisation of a field propagating in a birefringent single-mode optical fibre. The explicit dependence of the degree of polarisation on pulse duration, coherence time of the source and chromatic delay of the fibre is derived.     

海底光缆结构与发展

简要介绍了海底光缆结构,对海底光缆一般技术要求及结构的发展趋势作了简单说明.     

长距离海底光缆系统的技术动向

随着全球经济一体化和各国实现自身信息化的需求,国际间的通信和信息流量激增,尤其是以因特网为首的多媒体通信急剧发展,４５Ｍｂ／ｓ、１５５Ｍｂ／ｓ国际数字专用线业务的需求量逐年增加,造成了通信容量不足,因此为海底光缆通信提供了广阔的市场空间。本文将对长距离光放大海底光缆系统的开发现状、主要技术和发展动向进行探讨。     

Studies on designing of submarine optical fiber cable

This paper describes important studies necessary to design submarine optical fiber cables. These include a study for deciding the optimum single-mode fiber parameters to suppress losses during cabling, cable laying, and so on. It also includes a study on the necessary fiber proof test conditions to prevent fiber breakage during cable handling, that is, during cable laying and recovery and to assure long-term fiber reliability. Submarine optical fiber cable sea trial results are also stated for cables designed applying these studies.     

Strain of optical fibres of an optical submarine cable on the sea bed

The letter describes strain of optical fibres of an optical submarine cable on the sea bed. The test results of the sea trial show that the strain of optical fibres will be relaxed by the lower temperature and the higher pressure on the sea bed.     

Power spectrum of fibre output fluctuation in polarisation-preserving optical fibres

The power spectrum of fibre output intensity fluctuation was measured over 1.0 × 10?3 to 1.0 Hz for elliptical-jacket, PANDA and twisted fibres. Peaks peculiar to the mode conversion effect were observed for the linearly birefringent fibre, while the twisted fibre showed flat frequency characteristics with a reduced fluctuation level.