Remote Pumping Research Articles

PROGRESS IN OPTICAL FIBER AMPLIFIERS

Recent progress in fiber amplifier technology is reviewed. Broad band and high power are currently the key goals in the field of fiber amplifiers in conjunction with amplified system development. Broad-band EDFAs using fluoride-based hosts and high-power EDFAs with powerful pump lasers are described in detail. Recent progress and other requirements for optical amplifiers i.e. high gain, low noise, and high reliability, are all reviewed. The limitations in relation to achievable gain are described as well as the highest gain ever achieved. A method for its reduction are described. In relation to reliability, this paper mainly focuses on fluoride fiber. Recent progress on the main characteristics of 1.3 µm PDFA is reviewed and transmission experiment are described. Several attempts to construct fiber amplifiers operating at 0.8 µm, 1.4 µm, and 1.65 µm are also reviewed. In the field of amplified systems, WDM and remote pumping TDM techniques are a high priority. In particular, various WDM experiments such as long-distance WDM transmission, WDM soliton transmission, and WDM networks are all described in detail.

Safety factors in the remote control of infusion devices.

We have been using computer driven injections in surgery for many years to the benefit of more than thousand patients. Along these years we accumulated extensive experience in remote controlled infusion pumps. Today we have solved many communication problems. Despite the attention and care we brought in our software developments we still meet with some problems.

Single fibre repeaterless transmission over 490 km at 2.488 Gbit/s using a remote preamplifier and dispersion compensation

A cost effective repeaterless system with remote pumping in a single fibre is reported. Omitting dedicated pump fibres, 490 km transmission is demonstrated at 2.488 Gbit/s with a fibre loss of 87.4 dB. The system employs a remote preamplifler and dispersion compensating fibre, but no remote post-amplifier.

Nd:YLF Pumped Grating-Feedback Er3+:Yb3+Co-Doped Silica Fiber Laser Operating at 1.49 μm

We demonstrate for the first time a 1.49-μm Er3+:Yb3+co-doped silica fiber laser with fiber Bragg grating feedback, pumped with a diode-pumped Nd:YLF laser at 1.047 μm, which can be used for remote pumping of EDFAs. We examine both the potential and limitations of this laser as a high power source and point out how an efficient, high power laser could be realized. The maximum demonstrated output power, 21 mW, was limited by the cavity losses, by the strong ASE at the peak gain wavelength 1.535 μm, and by a “bottleneck effect” in the energy transfer between ytterbium and erbium with a corresponding reduced pump absorption at higher pump powers. By overcoming these limitations an output power in excess of 500 mW with 1 W of pump power is predicted.

Comment: Optical amplifier noise-figure reduction using a variable polarisation beam splitter

In conclusion, we have demonstrated an efficient tunable solid- state laser-pumped Er fibre amplifier and laser, with a slope effi- ciency of 55%. Developments in high power (>IOW) compact diode laser pumped Nd based solid state lasers as the pump source for the tunable Cfl+:YAG pump laser of the amplifier, point to power scalability and should allow saturated powers from Er3+ based fibre amplifiers > 30dBm in simple single-pump source- single fibre amplifier element geometries. These moderately effi- cient high power CF:YAG pump lasers may be attractive for remote pumping applications of Er)' based systems. Acknowledgments: The financial support of the EPSRC for this research is gratefully acknowledged. The contribution of the Royal Society is also acknowledged. Y.P. Tong and K. Rottwitt gratefully acknowledge the personal financial support of the National Science Council of Taiwan and the Danish Technical Research Council, respectively.

A nitrogen laser excited by a nanosecond microwave discharge

Experimental results on excitation of a nitrogen laser by means of a nanosecond microwave discharge in a wave beam are presented. The possibility of producing an atmosphere laser with remote microwave pumping is demonstrated. The numerical model for the nitrogen laser excited by a nanosecond discharge in a cylindrical TE wave in a tube and in free space is constructed. It is shown that, by changing the pressure of the laser mixture, the diameter of the gas discharge tube and the value of incident microwave power one can efficiently control the discharge parameters and achieve total absorption of microwave radiation and high efficiency of laser generation.

407-km, 2.5-Gbit/s repeaterless transmission using an electroabsorption modulator and remotely pumped erbium-doped fiber post- and pre-amplifiers

Using an integrated laser/electroabsorption modulator transmitter, a remotely pumped postamplifier and a remotely, pumped preamplifier, a repeaterless transmission distance of 407 km over nondispersion shifted fiber is achieved at 2.5 Gbit/s. This experiment takes full advantage of high power 1480 nm pump laser diode modules through optimized remote pumping configurations and benefits from the good behavior of the electroabsorption modulator transmitted waveform in presence of fiber nonlinearity and chromatic dispersion. >

Theoretical evaluation and record experimental demonstration of budget improvement with remotely pumped erbium-doped fiber amplification

The budget improvement achievable with different remote pumping schemes is presented. The calculations take into account Raman amplification and Rayleigh backscattering. The authors also report an experiment-without an in-line optical isolator-demonstrating a record budget improvement: an additional 8 dB compared to a 960-nm-pumped local preamplification.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Photovoltaic-powered water pumping-design, and implementation: case studies in Wyoming

A photovoltaic-powered water pumping project comprising of several rural electric cooperatives and their customers is described in detail. A number of remote water pumping installations in the state of Wyoming, USA, are currently operating as a result of this project. The design, installation and performance monitoring of these systems are discussed. In general, it can be stated that PV-powered water pumping in this state has been a cost-effective alternative to distribution line extension or other conventional means of water pumping. Customer satisfaction, in terms of functional adequacy and low maintenance requirements of these systems, is high. The benefit for the electric utilities concerned, are cost savings and better customer relations.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Chronically Instrumented Conscious Dog Model in Cardiovascular Toxicology Studies

A chronically instrumented dog model has been developed to conduct preclinical studies of the cardiovascular pharmacology and toxicology of pharmaceuticals. Eight conscious, unrestrained dogs can be simultaneously studied while cardiovascular signals are acquired through the use of flexible tethers, sealed mercury rotary connectors, and digital data acquisition and analysis systems. Test articles can be administered by either oral or intravenous routes. Intravenous infusions are performed via indwelling cannulae and remote controlled infusion pumps. The principle of operation is explained for implantable micromanometers, and sonomicrometers as well as electromagnetic, transit time, and Doppler blood flowmeters. Historical references are provided for the development of several of these devices. Techniques are described to perform aseptic thoracotomy surgery and to implant devices to measure cardiac left ventricular and aortic blood pressure, left ventricular wall thickness or segment length, and blood flow...

Reliability, cost, and performance of PV-powered water pumping systems: a survey for electric utilities

Opportunities for electric utilities to utilize photovoltaic-powered systems to serve small utility and customer-owned loads have been documented by the Electric Power Research Institute and others. One application where PV-powered systems can save money for utilities and their customers is remote water pumping for ranch, farm, and domestic use. Information on system reliability, cost, and performance is key to utility management decisions regarding this alternative approach to serving their customers. A project was initiated by EPRI to obtain this information on PV-powered pumping systems installed in the western US. With assistance from three PV-pumping system suppliers, a survey was developed and mailed to 251 owners of PV-powered water pumping systems installed in the last five years. This paper presents the summary of the findings of that survey and includes information on owner preferences, system reliability and performance, and cost data. >

Performance improvement of direct detection systems using local and/or long-distance pumped fiber amplifiers

Abstract Erbium-doped fiber amplifiers (EDFAs) in eight different system configurations are investigated, using a full-scale model, and the midline placement of the amplifier is shown to be optimal. A distributed amplifier compared to the remote pumping scheme shows no system improvement. Use of a booster (next to the transmitter), a midline remote-pumped amplifier, and a preamplifier (next to the receiver) allows up to 180 km of extra transmission fiber to be added.

Transmission length improvement in 2.5 Gbit/s direct detection system with Er-doped fibre amplifiers by efficient remote pumping

An efficient remote pumping scheme for Er-doped fibre amplifiers (EDFAs) is investigated using a highly accurate model. The transmission length improvement in a 2.5 Gbit/s direct detection system is evaluated.

Modification of a piston-type perfusion pump for delivery of low flow rates

A new remote pumping head and valve unit has been constructed to allow the delivery of low flow rates (with 0.05–0.3 ml stroke volume) from a Harvard Instruments blood pump.

System for Regulation of Combined Sewage Flows

The Municipality of Metropolitan Seattle has installed a computer directed control system which provides centralized control of regulator and pumping stations on trunk and interceptor sewers. The system will represent a procedure for regulation of combined sewage flows through use of available storage in trunk and interceptor sewer to reduce or eliminate overflows. The equipment includes the computer based central facility and automatic controls for 36 remote pumping and regulator stations. A procedure has been developed for automatic control using the rule curve technique. The central facility includes an operator oriented console and facilities for background data processing. Communication with remote stations is over leased telephone lines. The equipment at each remote station is designed for failsafe operation to return to local control in an orderly manner in the event of failure of the central station equipment or communication lines.

Supervisory‐Control System for the New Haven Water Co.

In 1962, the New Haven (Connecticut) Water Company installed a complete supervisory control system. A supervisory control system requires the transmission of a large number of different functions, either intermittently or continuously, in either or both directions. In order for a supervisory control system to be economically feasible, the transmission must be accomplished over a single interconnecting circuit. Of the several methods available, New Haven selected the method of frequency discrimination using audiotone equipment. The supervisory control systems that were installed by the New Haven utility provide for the operation of remote pumping stations and remote system‐regulating valves. In this article, only the control of remote pumping stations is discussed.

Use of a Remote Hydraulic Pump and Ram with a Lutz Type Bulk Density Sampler

Use of a Remote Hydraulic Pump and Ram with a Lutz Type Bulk Density Sampler

Probable Accuracy in Proportional Pacing Systems

UNTIL recently, the operator of a water treatment plant had to make all control adjustments manually and at various places around the plant. Pumps had to be started and stopped, valves opened and closed, chemical dosages adjusted, and chemical tests performed. Now, the skills of scientists and engineers are changing the picture. Remote controllers start and stop pumps and open and close valves. Pacing devices which operate according to water flow, automatically control chemical feeders. Automatic in-

Remote Pump and Valve Controls

Journal AWWAVolume 45, Issue 2 p. 121-128 Article Remote Pump and Valve Controls Leslie Paul, Leslie PaulSearch for more papers by this author Leslie Paul, Leslie PaulSearch for more papers by this author First published: 01 February 1953 https://doi.org/10.1002/j.1551-8833.1953.tb15966.xCitations: 1AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume45, Issue2February 1953Pages 121-128 RelatedInformation