Showing papers by "James Taylor published in 2003"

Short-term electricity demand forecasting using double seasonal exponential smoothing

Abstract: This paper considers univariate online electricity demand forecasting for lead times from a half-hour-ahead to a day-ahead. A time series of demand recorded at half-hourly intervals contains more than one seasonal pattern. A within-day seasonal cycle is apparent from the similarity of the demand profile from one day to the next, and a within-week seasonal cycle is evident when one compares the demand on the corresponding day of adjacent weeks. There is strong appeal in using a forecasting method that is able to capture both seasonalities. The multiplicative seasonal ARIMA model has been adapted for this purpose. In this paper, we adapt the Holt-Winters exponential smoothing formulation so that it can accommodate two seasonalities. We correct for residual autocorrelation using a simple autoregressive model. The forecasts produced by the new double seasonal Holt-Winters method outperform those from traditional Holt-Winters and from a well-specified multiplicative double seasonal ARIMA model.

Visual, Cognitive, and Language Assessments at 39 Months: A Follow-up Study of Children Fed Formulas Containing Long-Chain Polyunsaturated Fatty Acids to 1 Year of Age

Abstract: Objective. Docosahexaenoic acid (DHA) and arachidonic acid (ARA) are long-chain polyunsaturated fatty acids found in breast milk and recently added to infant formulas. Their importance in infant nutrition was recognized by the rapid accretion of these fatty acids in the brain during the first postnatal year, reports of enhanced intellectual development in breastfed children, and recognition of the physiologic importance of DHA in visual and neural systems from studies in animal models. These considerations led to clinical trials to evaluate whether infant formulas that are supplemented with DHA or both DHA and ARA would enhance visual and cognitive development or whether conversion of linoleic acid and α-linolenic acid, the essential fatty acid precursors of ARA and DHA, respectively, at the levels found in infant formulas is sufficient to support adequately visual and cognitive development. Visual and cognitive development were not different with supplementation in some studies, whereas other studies reported benefits of adding DHA or both DHA and ARA to formula. One of the first trials with term infants that were fed formula supplemented with DHA or both DHA and ARA evaluated growth, visual acuity (Visual Evoked Potential; Acuity Card Procedure), mental and motor development (Bayley Scales of Infant Development), and early language development (MacArthur Communicative Developmental Inventories). Growth, visual acuity, and mental and motor development were not different among the 3 formula groups or between the breastfed and formula-fed infants in the first year of life. At 14 months of age, infants who were fed the formula with DHA but no ARA had lower vocabulary production and comprehension scores than infants who were fed the unsupplemented control formula or who were breastfed, respectively. The present follow-up study evaluated IQ, receptive and expressive vocabulary, visual-motor function, and visual acuity of children from the original trial when they reached 39 months of age. Methods. Infants were randomized within 1 week after birth and fed a control formula ( n = 65), one containing DHA ( n = 65), or one containing both ARA and DHA ( n = 66) to 1 year of age. A comparison group ( n = 80) was exclusively breastfed for at least 3 months after which the infants continued to be exclusively breastfed or were supplemented with and/or weaned to infant formula. At 39 months, standard tests of IQ (Stanford Binet IQ), receptive vocabulary (Peabody Picture Vocabulary Test-Revised), expressive vocabulary (mean length of utterance), visual-motor function (Beery Visual-Motor Index), and visual acuity (Acuity Card Procedure) were administered. Growth, red blood cell fatty acid levels, and morbidity also were evaluated. Results. Results were analyzed using analysis of variance or linear regression models. The regression model for IQ, receptive and expressive language, and the visual-motor index controlled for site, birth weight, sex, maternal education, maternal age, and the child’s age at testing. The regression model for visual acuity controlled for site only. A variable selection model also identified which of 22 potentially prognostic variables among different categories (feeding groups, the child and family demographics, indicators of illness since birth, and environment) were most influential for IQ and expressive vocabulary. A total of 157 (80%) of the 197 infants studied at 12 months participated in this follow-up study. Characteristics of the families were representative of US families with children up to 5 years of age, and there were no differences in the demographic or family characteristics among the randomized formula groups. As expected, the formula and breastfed groups differed in ethnicity, marital status, parental education, and the prevalence of smoking. Sex, ethnicity, gestational age at birth, and birth weight for those who participated at 39 months did not differ from those who did not. The 12-month Bayley mental and motor scores and 14-month vocabulary scores of the children who participated also were not different from those who did not. At 39 months, IQ, receptive and expressive language, visual-motor function, and visual acuity were not different among the 3 randomized formula groups or between the breastfed and formula groups. The adjusted means for the control, ARA+DHA, DHA, and breastfed groups were as follows: IQ scores, 104, 101, 100, 106; Peabody Picture Vocabulary Test, 99.2, 97.2, 95.1, 97.4; mean length of utterance, 3.64, 3.75, 3.93, 4.08; the visual-motor index, 2.26, 2.24, 2.05, 2.40; and visual acuity (cycles/degree), 30.4, 27.9, 27.5, 28.6, respectively. IQ was positively associated with female sex and maternal education and negatively associated with the number of siblings and exposure to cigarette smoking in utero and/or postnatally. Expressive language also was positively associated with maternal education and negatively associated with the average hours in child care per week and hospitalizations since birth but only when the breastfed group was included in the analysis. The associations between maternal education and child IQ scores are consistent with previous reports as are the associations between prenatal exposure to cigarette smoke and IQ and early language development. Approximately one third of the variance for IQ was explained by sex, maternal education, the number of siblings, and exposure to cigarette smoke. Growth achievement, red blood cell fatty acid levels, and morbidity did not differ among groups. Conclusions. We reported previously that infants who were fed an unsupplemented formula or one with DHA or with both DHA and ARA through 12 months or were breastfed showed no differences in mental and motor development, but those who were fed DHA without ARA had lower vocabulary scores on a standardized, parent-report instrument at 14 months of age when compared with infants who were fed the unsupplemented formula or who were breastfed. When the infants were reassessed at 39 months using age-appropriate tests of receptive and expressive language as well as IQ, visual-motor function and visual acuity, no differences among the formula groups or between the formula and breastfed groups were found. The 14-month observation thus may have been a transient effect of DHA (without ARA) supplementation on early vocabulary development or may have occurred by chance. The absence of differences in growth achievement adds to the evidence that DHA with or without ARA supports normal growth in full-term infants. In conclusion, adding both DHA and ARA when supplementing infant formulas with long-chain polyunsaturated fatty acids supports visual and cognitive development through 39 months.

Efficacy and safety of echinacea in treating upper respiratory tract infections in children: a randomized controlled trial.

Abstract: ContextEchinacea is a widely used herbal remedy for treatment of upper respiratory tract infections (URIs). However, there are few data on the efficacy and safety of echinacea in treating URIs in children.ObjectivesTo determine if Echinacea purpurea is effective in reducing the duration and/or severity of URI symptoms in children and to assess its safety in this population.Design, Setting, and ParticipantsRandomized, double-blind, placebo-controlled trial of healthy children 2 to 11 years old recruited from a regional practice-based network and an alternative medical center in 4-month periods from 2000 through 2002.InterventionsStudy patients were randomized to receive either echinacea or placebo for up to 3 URIs over a 4-month period. Study medication was begun at the onset of symptoms and continued throughout the URI, for a maximum of 10 days.Main Outcome MeasuresPrimary outcomes were duration and severity of symptoms and adverse events recorded by parents; secondary outcomes included peak severity of symptoms, number of days of peak severity, number of days of fever, and a global assessment of severity of symptoms by parents of study children.ResultsData were analyzed on 707 URIs that occurred in 407 children, including 337 URIs treated with echinacea and 370 with placebo. There were 79 children who completed their study period without having a URI. The median duration of URIs was 9 days (95% confidence interval, 8-10 days); there was no difference in duration between URIs treated with echinacea or placebo (P = .89). There was also no difference in the overall estimate of severity of URI symptoms between the 2 treatment groups (median, 33 in both groups; P = .69). In addition, there were no statistically significant differences between the 2 groups for peak severity of symptoms (P = .68), number of days of peak symptoms (1.60 in the echinacea group and 1.64 in the placebo group; P = .97), number of days of fever (0.81 in the echinacea group vs 0.64 in the placebo group; P = .09), or parental global assessment of severity of the URI (P = .67). Overall, there was no difference in the rate of adverse events reported in the 2 treatment groups; however, rash occurred during 7.1% of the URIs treated with echinacea and 2.7% of those treated with placebo (P = .008).ConclusionsEchinacea purpurea, as dosed in this study, was not effective in treating URI symptoms in patients 2 to 11 years old, and its use was associated with an increased risk of rash.

Continuous-wave, high-power, Raman continuum generation in holey fibers.

Abstract: The possibility of using low pump power for cw Raman continuum generation is demonstrated by optimization of the pump peak power and by accounting for the loss-related reduction of the effective length of Raman interaction in holey fibers. A 3.8-W, 324-nm-wide cw Raman continuum with a spectral power density higher than 10 mW/nm is generated in a completely fiber-integrated, single-mode format.

All-fiber chirped pulse amplification using highly-dispersive air-core photonic bandgap fiber.

Abstract: We show, for the first time to our knowledge, all-fiber chirped pulse amplification using an air-core photonic bandgap fiber. Pulses from a wavelength- and duration-tunable femtosecond/picosecond source at 10 GHz were dispersed in 100 m of dispersion compensating fiber before being amplified in an erbium-doped fiber amplifier and subsequently recompressed in 10 m of the anomalously dispersive photonic bandgap fiber. Pulses as short as 1.1 ps were obtained. As air-core fibers present negligible nonlinearity, the presented configuration can potentially be used to obtain ultra-high pulse peak powers. A study of the air-core fiber dispersion and dispersion slope is also presented.

Totally fiber integrated, figure-of-eight, femtosecond source at 1065 nm.

Abstract: We report on generation of 850fs mode-locked pulses at 1065nm in a completely fiber integrated format. The figure-of-eight, fiber laser source incorporates anomalous dispersion compensation by using a holey fiber and a short length, high gain, double-clad Yb-fiber amplifier.

Effectiveness of an educational intervention in modifying parental attitudes about antibiotic usage in children.

Abstract: Objective. To determine the effectiveness of educational materials in improving the attitudes of parents of young children about the judicious use of antibiotics. Methods. We conducted a randomized controlled trial by recruiting parents of children who were younger than 24 months and being seen for any reason in primary care pediatric offices. At the time of enrollment, study parents indicated their level of agreement with 16 statements, including 9 statements about antibiotic usage and 7 about injury prevention. After being randomized, parents received either a pamphlet and a videotape promoting the judicious use of antibiotics (intervention group) or brochures about effective injury prevention (control group). Six weeks after enrollment, each group received another copy of the pamphlet or brochures and a follow-up questionnaire with the identical 16 statements. Responses on both questionnaires were transformed to an ordinal scale for analysis. Scores on the follow-up questionnaire for each statement about antibiotic use and injury prevention in the 2 groups were compared using linear regression, after controlling for the score obtained for the statement at enrollment. Results. We enrolled a total of 499 eligible parents in the study; 358 (72%) completed the follow-up questionnaires. At study entry, there were no significant differences between parents in the intervention and control groups regarding attitudes for 15 of the 16 statements assessed. However, 6 weeks after receiving the antibiotic educational materials, parents in the intervention group had significantly different attitude scores for 5 of the 9 statements about the antibiotic use. In each case, the scores reflected attitudes that would promote the judicious use of antibiotics. We found significant attitudinal change for statements about the use of antibiotics for specific conditions in children; there were no differences between the 2 groups for more general or theoretical statements about antibiotic use. Conclusions. A simple educational effort was successful in modifying parental attitudes about the judicious use of antibiotics. Information about specific childhood conditions may be more effective in changing attitudes than more general information about antibiotic usage.

Tunable repetition-rate multiplication of a 10 GHz pulse train using linear and nonlinear fiber propagation

Abstract: The temporal Talbot effect and soliton propagation in an optical fiber were exploited to yield a series of pulse train sources with tunable repetition rate simply through variation of the pulse train power in sections of the fiber. In a dual-repetition-rate configuration, 10 and 20 GHz or 10 and 30 GHz repetition rates could be achieved depending on the fiber length used, with pulse durations lower than 21 ps. In a triple-repetition-rate configuration, 10, 20, and 30 GHz repetition rates were obtained, with pulse durations lower than 15 ps.

Soliton self-frequency shift in highly nonlinear fiber with extension by external Raman pumping

Abstract: A completely fiber-integrated, wavelength-tunable subpicosecond pulse source is demonstrated using the soliton self-frequency shift in highly nonlinear dispersion-shifted fiber from a 1.56-μm 10-GHz 400-fs signal. Solitons as short as 100 fs are obtained at tunable wavelengths as high as 1.72 μm . Raman gain from an external pump is used to extend the soliton self-frequency shift to longer wavelengths.

Experimental characterisation of Raman gain efficiency of holey fibre

Abstract: The Raman gain efficiency of a 2.3 /spl mu/m-core-diameter holey fibre was measured using three different techniques. A /spl sim/4.65/spl times/10/sup -3/ W/sup -1/ m/sup -1/ efficiency is obtained by all techniques with mismatches lying within the estimated errors. It is shown that the high efficiency is due to small mode-field diameter of the holey fibre, as expected. The use of the fibre as a continuous-wave-pumped Raman amplifier is discussed.

Short-pulse, all-fiber, Raman laser with dispersion compensation in a holey fiber

Abstract: The use of Raman gain in conventional fiber followed by dispersion compensation in a holey fiber in a synchronously pumped laser configuration allowed compression by a factor of 8.5 of output pulses at a selected wavelength with respect to the pump pulses. We obtained 2-ps output pulses at 1.14 μm from a totally fiber-integrated laser pumped with 17-ps pulses at 1 μm . Higher pulse compression should be possible with nonlinear chirp compensation. Ultrashort-pulse, all-fiber Raman lasers at wavelengths shorter than 1.3 μm are feasible.

Using supply chain information: mapping pipfruit and kiwifruit quality

Abstract: Fresh produce supply chains are being transformed by increasing demands for information on product origin, production inputs, environment impacts and quality. A key point of differentiation between competing supply chains is their ability to transfer information seamlessly throughout the chain. Frequently, information required by the postharvest and/or marketing components of the supply chain must be sourced directly from the producer. Increasingly, the information sought from the producer needs to be based on complex data collected under a wide range of field conditions. This paper reports on techniques that can add value to the information required of the producer for all chain participants. These techniques include geographic information systems, handheld data capture devices, remote sensing equipment and database management at different levels in the supply chain. Also, the information generated from these techniques can be used to optimise physical and financial aspects of horticultural production systems, in addition to the provision of auditable product traceability. This aspect may help to motivate improvements to current information systems. While there are exciting opportunities for further progress, horticultural production and its supply chain has challenging demands for these technologies, not the least of which is the question “how will it work in practice?” Mapping of pipfruit and kiwifruit information provides case studies that explore the implications, and identify current limitations, for researchers, developers and users of the various technologies. INTRODUCTION The key to a successful supply chain is matching consumer requirements with timely and cost effective product supply. Modern industrialised supply chains for perishable product are currently undergoing major changes. Aggregation and differentiation of these chains, for competitive advantage, is being facilitated by innovative technology, in addition to new food safety and security concerns (Opara, 2003). These chains are also adopting strategies based on new understandings in supply chain theory (Mowat and Collins, 2000). Track and Trace. There is a growing need for improved knowledge of product origin and traceability of product through the supply chain. The driver for this is the ability to provide evidence of Good Management Practice (GMP). There is also a need for improved segregation in order to allow individual supply chains to extract the maximum revenue from increasingly sophisticated future market segments. Availability of new technologies, such as electronic tags, security devices and improved web-based tools, has also hastened the development of track and trace (Praat et al. 2001). Product Quality. For fresh produce chains, which are under increasing competition from both minimally processed and fully processed products, consistency of quality product is critical. Variability in quality attributes such as size, colour, shape, flavour, sweetness and firmness all detract from the value proposition at the point. Sources of variability arise from both the pre and post-harvest conditions and handling of Proc. Int. Conf. Quality in Chains Eds. Tijskens & Vollebregt Acta Hort. 604, ISHS 2003 378 the crop. Little is currently made in terms of managing this variability as this information is not relayed back to growers. If producers are to be rewarded for optimising their quality and produce a more uniform product, then systems are required to facilitate this. Consumer Interaction. An important aspect of supply chain theory is the linking of producers to consumers (Aulagnier, 1993), as producers need to know what are the attributes that the consumer values. With this information, the supply chain aims to optimise the supply of fruit that meets these needs as well as the inherent constraints of the supply chain. In general, the quality attributes recorded are based on visual characteristics, providing minimal feedback to producers on the critical determinants of value. However, with the advent of new non-destructive technologies, such as Near Infrared Spectroscopy (NIR), density or impact force sensors have been developed to provide information on internal fruit quality attributes such as dry matter, soluble solids and fruit firmness (Kawano, 2001). With access to such information, it is expected that the supply chains ability to respond to the consumer will improve. through positive feedback, with growers optimising fruit quality in response to greater market demand. Global Information System. Tools that improve the information shared by chain stakeholders are expected to facilitate improvement in the overall supply chain performance. In the broadest terms these tools need to provide the means to enable a free flow of relevant information that is available to all the relevant participants in the supply chain. For instance, in the case of EUREP – (GAP), such a system needs to provide retailers and consumers with specific information on the grower and how the crop has been grown. In addition, the retailer can provide feedback on in-market quality assessments to growers, who can, if required, trace back to areas within their orchard. While the overall concept of improving information management systems for the supply chain is a large and complex issue, it may only be solved by addressing individual aspects. Information Sources. There is a significant amount of data collected within a supply chain that is never shared. Often such data is collected for a specific purpose. For example, coolstore temperature data is frequently monitored to ensure correct performance of the refrigeration, but this data could also be used in models that predict shelf life and quality at point of sale. Another major source of information is the packhouse grader. While a grader singulates each fruit and segregates fruit on the basis a number of quality attributes, this device can also stored the attributes measured for each fruit. For example, New Zealand apple graders currently measure fruit weight (size) and colour and kiwifruit graders measure weight, brix and dry matter (using NIR for the latter two attributes). With the ongoing development of additional sensors even more information will become available. Although the currently collected information is retained at the packhouse or distributed to the grower it could, in principal, be used more widely within the supply chain. Packhouses currently supply this quality information back to growers in a summarised form. Table 1 provides an example of this for one of the kiwifruit orchards under study. We postulated that the value of the data can only be truly realised when the information is summarised at a significantly more detailed, site specific level, as it gives growers better information on which to base their management decisions. Examples from our work with apple and kiwifruit, demonstrate how grader data may be better utilised within their respective supply chains. Also, we will show how to manage and display exemplary data from the supply chain within a Geographical Information System (Arcview GIS) as an alternative to the traditional tabular form that growers currently receive. The profitability of an orchard is primarily determined by the value and quantity of fruit produced and the cost to achieve this production. In the case of apples, value can be determined by; variety; fruit size, colour and the quantity of fruit that is of export standard. The value for kiwifruit is similarly structured with differential payments for different sizes and a premium paid for high flavour (high dry matter) fruit. Current situation. Fruit tracking systems in New Zealand comprise a range of manual and electronic techniques. Fruit are picked into bins, which may have individual labels. Once the fruit reaches the packhouse individual bins are aggregated into variety or

Gain-flattened fiber Raman amplifiers with nonlinearity-broadened pumps.

Abstract: Gain flattening of an E-band (1360-1460-nm) fiber Raman amplifier was achieved by pump spectral broadening to a 16.3-nm linewidth by use of nonlinearity in a 6.2-km standard fiber. With the broadened pump, the characteristic Raman gain ripple was removed and the 3-dB gain bandwidth was increased by 10.6 nm relative to the nonbroadened pump case. The experimental results agreed well with a gain profile simulation. The use of a 100-m holey fiber for pump broadening was also investigated near 1.56 microm for U-band (1625-1675-nm) Raman amplifiers. Much less broadening was observed, which is believed to be a result of less four-wave mixing.

CORRIGENDUM CORRIGENDUM TO “COCAINE-INDUCED PROLIFERATION OF DENDRITIC SPINES IN NUCLEUS ACCUMBENS IS DEPENDENT ON THE ACTIVITY OF CYCLIN-DEPENDENT KINASE-5” [Neuroscience 116 (1) 19–22]

Abstract: S. D. NORRHOLM,* J. A. BIBB, E. J. NESTLER, C. C. OUIMET, J. R. TAYLOR AND P. GREENGARD Program in Neuroscience, Department of Psychology, The Florida State University, 251 Biomedical Research Facility, Tallahassee, FL 32306, USA Laboratory of Molecular and Cellular Neuroscience, The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA Department of Psychiatry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9070, USA Department of Psychiatry, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA

Fibre optical wavelength-converter employing cross-phase modulation and low-threshold non-adiabatic Raman compression

Abstract: Cross-phase modulation in highly nonlinear fibre and non-adiabatic Raman compression in dispersion-shifted fibre was employed to switch 20 GHz, 6 ps pulses to 3 ps solitons. Non-adiabatic compression has a low threshold and dispersive waves generated from non-adiabaticity can be removed using a nonlinear optical loop mirror.

Optical time-domain reflectometry of discrete fiber Raman amplifiers

Abstract: Optical time-domain reflectometry is proposed and demonstrated as a means to characterize the signal power evolution in discrete fiber Raman amplifiers. Up to /spl sim/20-dB-gain amplifiers have been characterized comprising different fibers, under copropagating and counterpropagating signal-pump configurations, and under saturated and unsaturated conditions. The results demonstrate the flexibility of this simple and useful amplifier characterization technique. Simulations show good agreement with experimental results, and sustain the reliability of the technique.

E-band fibre Raman amplifier and implications of 1.4 [micro sign]m water absorption

Abstract: An E-band Raman amplifier in nonzero dispersion fibre is demonstrated. 1.4 µm water absorption does not hinder the amplifier itself but its characterisation due to water vapour in the external measurement instruments. The E-band could be used to extend the optical telecommunications bandwidth using nonzero dispersion fibre-based systems.

All-solid-state diode-pumped modelocked Cr:LiSAF laser

Abstract: A diode-pumped Cr: LiSAF laser has been modelocked for the first time using a multiquantum well absorber in an external cavity to yield CW trains of picosecond pulses.

All-integrated Brillouin fiber ring laser using holey fiber

Abstract: An all-fiber Brillouin ring laser has been developed based on a /spl sim/100-m-long, 2.3-/spl mu/m-core-diameter holey fiber. The laser spectrum consisted of two interleaved counter-propagating combs of Stokes/anti-Stokes components that were separately extracted in a coupler.

All-fibre-integrated, femtosecond laser source at 1 /spl mu/m

Abstract: The first totally-fibre-integrated, figure-of-eight fs source at 1/spl mu/m is demonstrated. 850 fs pulses produced at the round-trip repetition-rate of the laser incorporating holey fibre and short length Yb-DFA. Alternative approaches to fs, Yb, all-fiber sources presented.

4W, completely fiber integrated, holey-fibre-based, Raman continuum source

Abstract: A completely fibre integrated, 4.1W white light source with 200-300nm width and 20mW/nm average spectral power density is reported by employing Raman continuum generation in holey fibre pumped with seeded Yb fibre source. Under 1dB loss holey fibre splices handled over 10.5W power

All-fiber continuous-wave parametric oscillator based on holey fiber

Abstract: A 1.55pm continuous-wave fiber parametric oscillator based on holey fiber is demonstrated. The signal presents a -3OdE3 extinction ratio and a linewidth as narrow as -1Opm. Up to six cascaded four-wave mixing orders are observed. 02002 Optical Society of America OCIS codes: (060.2320) Fiber optics amplifiers and oscillators, (190.4380) Nonlinear optics, four-wave mixing Fiber optical parametric oscillators (FOPOs) are flexible tunable sources, which potentially can generate light in several spectral regions. However, the low fiber nonlinearity has generally forced FOPOs to operate in pulsed regime. Recently, a continuous-wave FOPO utilizing highly -nonlinear fiber was demonstrated in a Fabry-Perot cavity [l]. Such a fiber allows much lower pump powers to be used but, as with conventional fibers, restricts the operating spectral region to the infrared, where single-mode and lowdispersion operation are achieved. Holey fibers (HFs), on the other hand, can be single-mode and have low dispersion over a much wider spectral region. A -750nm HF-based Fabry-Perot FOPO was demonstrated but employed a pulsed pump [2]. Here we demonstrate, for the first time to our knowledge, a continuous-wave HF-based FOPO. The FOPO consisted of an all-fiber ring and operated at 1.55pm. Threshold was reached for a 1.28W pump power and the signal had a -10pm linewidth and -3OdB extinction ratio. Fig. 1 shows the experimental setup. The pump comprised a tunable external-cavity laser that had its linewidth broadened in a phase modulator to suppress Brillouin scattering and that was amplified in a 3.5W erbiumdoped fiber amplifier (EDFA). It was inserted into the FOPO via a 0.8nm-bandwidth fiber Bragg grating (FElG) providing 97% reflectivity at 1550.6nm. The FBG had

Watts level, sum frequency generation in the red of synchronously seeded Yb and Er fiber sources

Abstract: Synchronous temporal pulsed seeding of high power fibre amplifiers at 1 and 1.5micron is proposed and demonstrated for efficient, single pass SFG in periodically poled KTP. 3.5W average power is obtained at 630nm.