Remote Pumping Research Articles

Theoretical analysis, optimization, and experimental evaluation of dual function DP R-EDFA

A simple rate-equation model of double pass (DP), remotely-pumped Erbium-doped fiber amplifier (R-EDFA) is developed based on the Giles-and-Desurvire (1991) model of a single pass (SP) EDFA. The mathematical equations to calculate stimulated absorption-and-emission rate between levels 1 and 2 of SP EDFA are modified by integrating the reflected backward-propagating signal of the DP R-EDFA. Besides the signal amplification, dispersion compensation by the chirped-fiber Bragg-grating (CFBG) inside the DP R-EDFA is also taken into account. The reflection losses of a signal by the CFBG are included in the backward-propagating signal of the DP R-EDFA. Considering a high gain and low noise figure (NF) by very low remote pump power as a main design objective, the design process of an optimized DP R-EDFA for a long haul optical-fiber-communication system (OFCS) is demonstrated. Robustness and stability of the DP R-EDFA rate-equation model developed are shown by analyzing the numerical results and output shapes using various design parameters of the DP R-EDFA. Finally, the DP R-EDFA rate-equation model developed is validated with the help of experimental results.

Numerical analysis and optimization of remotely pumped double pass Erbium doped fiber amplifier

A simple rate equation model of double pass (DP) Erbium doped fiber amplifier (EDFA) is developed based on the Giles and Desurvire (1991) model of single pass (SP) EDFA. The mathematical equations to calculate stimulated absorption and emission rate between level 1 and 2 of SP EDFA are modified by integrating the reflected backward propagating signal of DP EDFA. Reflection loss of signal by the reflector is included with the backward propagating signal of DP EDFA. A combination of Runge-Kutta and relaxation method is used to numerically solve the developed DP EDFA rate equation model. Considering high gain and low noise figure (NF) by very low remote pump power as main design objective, the design procedure of remotely pumped optimized DP EDFA is described. Finally the robustness and stability of the developed DP EDFA rate equation model are shown by analyzing the numerical results and output shape using various design parameters.

Owner Derived Tools for Collection System Asset Management; (1) Capacity and Condition ranking, (2) Remote Pump Station Monitoring, and (3) Probability and Severity Analysis.

Owner Derived Tools for Collection System Asset Management; (1) Capacity and Condition ranking, (2) Remote Pump Station Monitoring, and (3) Probability and Severity Analysis.

Design and Performance of Low-Loss Submarine Optical Fiber Cable for Long-Distance Submarine Repeaterless Transmission System Employing Remotely Pumped EDF and Distributed Raman Amplification

This paper describes a low-loss submarine optical fiber cable for a long-distance submarine repeaterless transmission system that employs remote pumping. The features of this system are that it has an increased signal power budget and is cost effective and easy to maintain. First, we investigated the relationship between the signal and pump losses and the Raman gain efficiency of optical fiber needed to achieve a submarine repeaterless transmission system operating at 2.5 Gbps and over a distance exceeding 370 km. We manufactured a submarine optical fiber cable based on the results and confirmed that it had low-loss characteristics. Second, we evaluated the long-term loss stability of the optical fiber with a high-power continuous wave (CW) laser light as the pump source. We confirmed that the loss remained unchanged after 1900 hours of exposure to 8W CW laser light at a wavelength of 1.48μm. This submarine optical fiber cable is being employed in a commercial submarine repeaterless transmission system between Okinawa and Miyakojima.

Submarine Optical Fiber Cable for Repeaterless Transmission Systems Employing Remotely Pumped EDF and Distributed Raman Amplification

We developed a submarine optical fiber cable for a repeaterless transmission system with remotely pumped erbium doped fiber (EDF) amplification and backward Raman amplification. We clarified the required optical fiber characteristics for a long-distance repeaterless transmission system designed to exceed 370 km at 2.5 Gbit/s. We examined various types of standardized fiber in terms of optical loss and Raman gain characteristics, and selected the most suitable. We then used this fiber in 6-fiber units to manufacture a submarine optical fiber cable, and examined the stability of the optical loss and Raman gain characteristics. We confirmed that the manufactured cable has stable characteristics, and is applicable to long-distance transmission with remote pumping systems.

Transfusion-Free Cardiopulmonary Bypass in Jehovah’s Witness Patients Weighing Less Than 5 kg

Performing cardiac surgery on pediatric Jehovah’s Witness patients is a great challenge for the surgical team and especially for the perfusionist. Jehovah’s Witnesses reject blood transfusions on the grounds of their literal interpretation of passages of the Bible. In accordance with this belief, Jehovah’s Witnesses feel that it is also forbidden to retransfuse autologous blood that has been separated from their own circulatory system. We report the use of cardiopulmonary bypass (CPB) during open-heart surgery in three infants with a body weight of 4.5 kg, 3.5 kg, and 3.1 kg, respectively, without transfusion of blood components. A small-volume CPB circuit with a priming volume of 200 mL, including the arterial line filter, was designed to decrease the degree of hemodilution. A dedicated pediatric heart lung machine console with remote pump heads and intensive blood conservation efforts allowed the operation without the use of donor blood. The CPB circuits were primed with crystalloid solution only. The procedures were performed in normothermia or in moderate hypothermia. Pre-CPB hemoglobin levels were 10.8 g/dL, 10.6 g/dL, and 8.5 g/dL. The hemoglobin concentrations measured during CPB ranged from 5.9 to 6.5 g/dL, 6.4 to 6.8 g/dL, and 5.5 to 5.9 g/dL, respectively. The patients did not receive any blood or blood products during their entire hospital stay.

Pump-to-signal FWM of co-pumped Raman amplifier for remote pumps supervisory

We propose a novel remote Raman pumps monitoring technique based on the pump-to-signal four-wave-mixing (FWM) in a 50-m long highly nonlinear dispersion-shifted photonic crystal fiber. The health information of the pumps can be reproduced to the new FWM signal accompanying the transmission signal through the pump-to-signal FWM. As a result, the modulation frequency limitation for cross gain modulation can be avoided effectively, and no degradation of the transmission system is induced by this technique.

Ultra-long-span 500 km 16×10 Gbit/s WDM unrepeatered transmission using RZ-DPSK format

Ultra-long-span 500 km 16×10 Gbit/s WDM unrepeatered transmission without dedicated fibre for remote pumping is successfully demonstrated for the first time. Enabling technologies are the RZ-DPSK format, forward pumped Raman amplification, and second-order backward pumped Raman amplification in combination with enlarged effective area SMF and conventional SMF.

Open Heart Surgery for Small Children Without Homologous Blood Transfusion by Using Remote Pump Head System

Background To avoid excessive hemodilution, the transfusion of a large amount of homologous blood may be required in open heart surgery for small children, which in turn, can cause a significant immunologic response. Methods Cardiopulmonary bypass systems with remote pump heads were used for patients weighing 5 kg or less that were undergoing ventricular septal defect repair. The procedures took place from January 1997 to August 2002. The surgery was started with bloodless prime in 122 out of 158 (77.2%) consecutive patients. Exclusion criteria were a predicted hematocrit after the initiation of bypass of less than 15%, respiratory failure or heart failure (or both), and pulmonary vascular obstructive disease. Results The mean age and body weight were 3.8 ± 1.8 months and 4.3 ± 0.5 kg, respectively. The priming volume was 181.0 ± 32.5 (minimum: 130) mL. The hematocrit after cardiopulmonary bypass was initiated was 16.7% ± 2.3%. Six patients required subsequent blood transfusion owing to postoperative complications that resulted in compromised hematopoiesis. In the rest, the hematocrit before discharge was 30.6% ± 3.0%. Renal and liver function tests were maintained within the normal range. Patients were extubated at 5.6 ± 2.8 hours after operation with proper oxygenation. Neurodevelopment was apparently normal. The Japanese psychomotor developmental scale assessment was given to patients without chromosomal abnormality between the ages of 1 and 3 years; the resulting score was 102.2 ± 15.4 (mean = 100 for normal population). Conclusions Open heart surgery was achieved without blood transfusion in the selected group of small children. The use of remote pump heads reduced the overall need for blood transfusions and possibly inflammatory reactions.

GABA in pedunculo pontine tegmentum regulates spontaneous rapid eye movement sleep by acting on GABA A receptors in freely moving rats

REM-OFF and REM-ON neurons in the brainstem are reported to regulate REM sleep, however, the detailed mechanism of generation of REM sleep is unknown. The former are continuously active except during REM sleep and an inhibitory neurotransmitter, GABA, has been implicated in mediating the inhibition for the generation of REM sleep. The REM-ON neurons, on the other hand, remain inactive throughout but increase firing during REM sleep. This study was conducted to investigate if GABA in the brain area rich in cholinergic REM-ON neurons would modulate REM sleep as proposed earlier. Rats were surgically prepared for sleep–wake recording and two cannulae aiming pedunculopontine areas in the brainstem that are rich in REM-ON neurons, were implanted bilaterally. After recovery, picrotoxin, a GABA A antagonist, was simultaneously microinjected bilaterally into the pedunculopontine area in freely moving normally behaving rats using a remote dual syringe pump and the effects were studied on electrophysiological sleep and waking parameters. The results showed that picrotoxin significantly reduced REM sleep for 6 h and the effect was due to reduction in the frequency of generation of REM sleep.

Oil level monitor added to range of positive displacement pumps

The Hydra-Cell D35 Series of industrial pumps from Wanner Engineering Inc is now available with an oil level monitor. The monitor detects dramatic oil level changes in the pump in order to minimize costly process interruptions and potential pump damage. The re-designed pump is intended for remote or critical pumping applications, such as automotive plants, oil refineries, chemical processing plants or paper mills. This is a short news story only. Visit www.worldpumps.com for the latest pump industry news.

Long term blocking of GABA-A receptor in locus coeruleus by bilateral microinfusion of picrotoxin reduced rapid eye movement sleep and increased brain Na–K ATPase activity in freely moving normally behaving rats

Isolated studies showed that norepinephrinergic REM-OFF neurons are active throughout except during rapid eye movement (REM) sleep when they are inhibited possibly by GABA. Similarly, independent studies have also reported that during REM sleep deprivation those REM-OFF neurons continue firing, that there is increased norepinephrine (NE) in the brain and that increased levels of NE increases the Na–K ATPase activity in the brain. However, it was not known if all those changes were directly related to REM sleep deprivation, what could be the mechanism for such changes and their patho-physiological significance. To confirm the same, based on the reports, mostly from our group, it was hypothesised that GABA antagonist in the locus coeruleus (LC) should at least significantly reduce REM sleep and simultaneously increase Na–K ATPase activity in the brain. To confirm the proposed hypothesis, picrotoxin, a GABA-A receptor antagonist, was bilaterally microinjected every 6 h for 36 h into the LC of freely moving normally behaving rats and the effects on electrophysiological signals signifying sleep-wakefulness and on brain synaptosome Na–K ATPase activity were estimated. The microinjection was done with the help of a remote control pump without handling or disturbing the rats. The findings that REM sleep was significantly reduced and there was associated increase in Na–K ATPase activity confirmed our hypothesis. The results also support our modified (GABA-mediated) model of neural connections in the LC for the regulation of REM sleep. Also, this is probably the first report to simulate REM sleep deprivation using receptor antagonist.

Low-loss submarine optical fibre cable for repeaterless submarine transmission system employing remotely pumped EDF and distributed Raman amplification

A low-loss submarine optical fibre cable for a long-distance repeaterless submarine transmission system employing remote pumping is described. The features of this system are an increased signal power budget and the provision of cost-effective submarine transmission systems that are easy to maintain. The relationship between the signal and pump losses of optical fibre needed to achieve a repeaterless submarine transmission system operating at 2.5 Gbit/s over a distance exceeding 370 km were investigated. A submarine optical fibre cable based on the results was manufactured and confirmed to have low-loss and stable transmission characteristics for practical applications in submarine repeaterless transmission systems.

Variable speed drives for remote downhole pump applications

Electrical submersible pumps are now widely used in subsea wells to provide artificial lift. This article describes some of the practical problems associated with motor performance when driven from variable-speed PWM drives connected to subsea motors via step-up transformers and potentially long HV cables.

Impact of a remote pump head on neonatal priming volumes.

Reduction of priming volumes of the cardiopulmonary bypass (CPB) circuit in neonatal cardiac surgery to decrease haemodilution and blood transfusion requirements can be achieved with the use of neonatal low prime oxygenators and smaller diameter tubing. We have further reduced our prime volume with the use of a custom-designed arm allowing for remote positioning of a double-headed roller pump. This arm enables the double pump to be placed alongside the main heart-lung machine close to the operating table, and to position the pump inlet and outlet tubing immediately at the reservoir outlet and oxygenator inlet, respectively, therefore reducing tubing lengths. Priming volumes of four cases using this configuration were compared to four cases using our standard neonatal bypass setup. Results showed a 29% decrease in priming volume and a 58% reduction in blood utilization during CPB. This reduction in priming volume is clinically significant as it lowers the ratio of priming volume to patient blood volume and reduces homologous blood requirements.

Proposal for an Er/sup 3+/-doped chalcogenide glass fiber upconversion laser operating at 980 nm and pumped at 1480 nm

We propose a novel fiber upconversion laser operating at 980 mn and pumped at 1480 nm, which will allow remote optical pumping of erbium-doped optical amplifiers. From the measured spectroscopy, we show Er/sup 3+/-doped gallium lanthanum sulphide glass to be a potential host for such a 1480-nm/980-nm upconversion laser. The small-signal gain is analyzed numerically and the lasing possibilities are discussed.

Gain optimisation of an erbium doped fibre for remotepumping system

The authors investigate the optimum length of erbium doped fibre (EDF) for a remote pumping system. The optimum EDF gain yielding the minimum total noise figure (NF) is calculated and experimental data support the theoretical analysis.

SUPER PON-a fiber to the home cable network for CATV and POTS/ISDN/VOD as economical as a coaxial cable network

A complete super PON fiber to the home cable network as economical as the classic coaxial cable network, designed for application in the local loop is presented. The concept uses high power lasers, remote pumped erbium doped fiber amplifiers (EDFAs) to reduce cost by high splitting ratio, economical receivers for the downstream direction and economical CD player lasers for the upstream direction. Several novel technical solutions for this application (a new method to avoid stimulated Brillouin scattering (SBS), remote pumping of the EDFA and a compensating technique to adapt the CD laser to the normal fiber) are presented.

Record 20-gigabit-per-second 200-km repeater span transoceanic soliton transmission using in-line remote pumping

The cost and the reliability of a transoceanic link depend widely on the number of line repeaters. The concept of inline remote pumping can be an interesting new solution to reduce its number. To demonstrate its feasibility, we have performed a 20-Gb/s soliton transmission over transoceanic distance and have succeeded in increasing the in-line active-units span up to a record distance of 200 km. Therefore, this experiment shows that soliton transmission permits both high data rates and repeater spans thanks to the use of the in-line regenerative control and the new in-line remote pumping techniques.

Single fibre repeaterless transmission over 490km 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.