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In this paper, the radiation shielding parameters such as linear attenuation coefficients (LAC, µ), mass attenuation coefficients (MAC, µ/ρ), effective atomic numbers (Zeff), effective electron densities (Neff), half value of layers (HVL) and mean free paths (MFP) were investigated for rare earth metal oxides (CeO2 and Er2O3) doped borosilicate (BS) glasses. The glass samples were manufactured by the mechanical alloying process CeO2, Er2O3, and BS powders. The radiation shielding parameters of the BS glass samples were determined at photon energies in the energy region of 22.16–59.54 keV using a high purity germanium detector. The theoretical results for MAC were obtained from WinXCom program. It was observed that theoretical and experimental results are compatible with each other. The radiation absorption increased with increasing the concentration of CeO2 and Er2O3 in the BS samples due to high density increasing with the concentration of CeO2 and Er2O3, which are high atomic mass. Furthermore, LAC, MAC, Zeff, and Neff values for CeO2 and Er2O3 doped BS glass decreased with increasing photon energy. While the MAC value at 59.54 keV energy level for pure BS sample was 0.242 cm2/g, it increased to 0.624 cm2/g with CeO2 addition and 0.838 cm2/g with the addition of Er2O3. The Z eff and N eff values of glass samples with Er2O3 were bigger than CeO2 doped glass samples owing to high atomic number. Consequently, it was determined that BS-Er2O3 glasses had better the radiation shielding capacity than BS-CeO2 glasses. [ABSTRACT FROM AUTHOR]

Graphene oxide mode-locked Er-doped fiber lasers are investigated in this paper. The generalized nonlinear Schrödinger equation, which can be used to describe the fiber lasers, is studied analytically. Soliton solutions for this equation are obtained, and the stable solitons are generated in the fiber lasers. Physical effects, such as the gain bandwidth, distributed gain, group-velocity dispersion, and nonlinearity of fiber lasers, are analyzed. Soliton amplification techniques are proposed which can effectively restrain the appearance of pedestals during the evolution of solitons in the cavity. These analytic results are compared with the experimental ones. The results of this paper will be valuable to the study of the fiber lasers properties and provide theoretical guidance for the obtaining of high-power ultra-short pulses. [ABSTRACT FROM AUTHOR]

In this paper, a multiwavelength two-mode Brillouin fibre laser generated by two-mode optical fibre (TMOF) is proposed and demonstrated experimentally. The system comprises a 500 m long TMOF. A tunable laser source amplified by a high power erbium doped fibre amplifier acts as the Brillouin pump (BP) followed by a single mode fibre Bragg grating as a reflector in the cavity with a centre wavelength of 1544 nm. The BP is observed in the superposition ofandmodes in the few-mode fibre. The set-up is capable of generating a maximum of 12 clearly defined Stokes lines at the pump power of 28.6 dBm, spanning from 1543.88 to 1544.92 nm. [ABSTRACT FROM PUBLISHER]

In this paper, lanthanum was used as a chemical modifier for the direct determination of erbium by high-resolution continuum source electrothermal atomic absorption spectrometry. A two-step experimental design was used for optimization, first a full factorial design was conducted for identification of significant factors, and then a central composite design was carried out for final optimization of the significant factors. The optimum parameters were obtained as follows: atomization temperature of 2500°C, pyrolysis temperature of 1600°C, and pyrolysis time of 10 s in the presence of lanthanum as a chemical modifier. Under optimum conditions, the characteristic mass, limit of detection, and limit of quantification were 29 pg, 0.71, and 2.4 µg L−1, respectively. The precision of the method, estimated as the relative standard deviation for 10 replicate measurements of 50 µg L−1of erbium, was 1.8%. The optimized method was applied to determine erbium content in sediments and rock samples. The determined values of erbium in sediment certified reference materials were in satisfactory agreement with the certified values according to thet-test for a 95% confidence level. [ABSTRACT FROM PUBLISHER]

Under investigation in this paper is a set of the-dimensional nonlinear Schrödinger–Maxwell–Bloch (NLS–MB) equations, which describes the optical pulse propagation in an erbium-doped fibre. Employing the Hirota method and symbolic computation, we obtain the one- two- and N-soliton solutions. We prove that the interactions between the two solitons are elastic through the asymptotic analysis on the soliton solutions. Figures are plotted to show the one soliton and the interaction between the two solitons. We find that the decrease of the frequency shift from the resonance can make the angle between the propagation directions and the amplitudes of the two MB solitons bigger, implying that the change of the amplitudes of the two MB solitons is closely related to the propagation directions of the two NLS solitons. [ABSTRACT FROM PUBLISHER]

In this paper, we construct soliton solutions for a generalized variable-coefficient coupled Hirota–Maxwell–Bloch system, which can describe the ultrashort optical pulse propagation in a nonlinear, dispersive fiber doped with two-level resonant atoms. Under certain transformations and constraints, one- and two-soliton solutions are obtained via the Hirota method and symbolic computation, and soliton collisions are graphically presented and analyzed. One soliton is shown to maintain its amplitude and shape during the propagation. Soliton collision is elastic, while bright two-peak solitons and dark two-peak solitons are also observed. We discuss the influence of the coefficients for the group velocity, group-velocity dispersion (GVD), self-phase modulation, distribution of the dopant, and Stark shift on the soliton propagation and collision features, with those coefficients are set as some constants and functions, respectively. We find the group velocity and self-phase modulation can change the solitons’ amplitudes and widths, and the solitons become curved when the GVD and distribution of the dopant are chosen as some functions. When the Stark shift is chosen as a certain constant, the two peaks of bright two-peak solitons and dark two-peak solitons are not parallel. In addition, we observe the periodic collision of the two solitons. [ABSTRACT FROM AUTHOR]

The aim of this paper is to present a novel laser technology utilizing the erbium YAG laser for various minimally invasive, non-surgical procedures in gynecology. Non-ablative, thermal-only SMOOTH-mode erbium pulses are used to produce vaginal collagen hyperthermia, followed by collagen remodeling and the synthesis of new collagen fibers, resulting in improved vaginal tissue tightness and elasticity. This erbium laser technology is used for treatments of vaginal laxity, stress urinary incontinence, pelvic organ prolapse and vaginal atrophy. In the period from 2010 to 2014, several clinical studies covering all four indications were conducted with the aim to prove the efficacy and safety of this novel technology. An overview is presented of the results of these studies where several objective as well as subjective assessment tools were used. The results have shown that SMOOTH-mode erbium laser seems to be an effective and safe method for treating vaginal laxity, stress urinary incontinence, pelvic organ prolapses and vaginal atrophy. [ABSTRACT FROM AUTHOR]

The genitourinary syndrome of menopause (GSM) and stress urinary incontinence (SUI) are common clinical challenges for women’s health and quality of life. The laser treatment and particularly the vaginal erbium laser (VEL) may provide a new non-invasive treatment for both GSM and SUI. However, the estimation of the ultimate results of different laser treatments may be altered by different issues, such as patient selection, concomitant treatments, and long-term effect of vaginal laser thermotherapy. In the present paper, we present the protocol for a large multicenter study on the evaluation of the efficacy and safety of VEL for the treatment of GSM and SUI, the Vaginal Erbium Laser Academy Study (VELAS). This study will evaluate the effects of three laser applications in 1500 postmenopausal women. Subjective and objective symptoms will be evaluated prior to the first laser treatment with follow-up visits after 4 weeks from the last laser application, and subsequently after every 3 months for 1 year. Findings from the VELAS have the potential to affect clinical care practice and health decisions for millions of women world-wide for a non-hormonal treatment for GSM and a non-invasive treatment of SUI. [ABSTRACT FROM PUBLISHER]

In this paper, coupled higher order nonlinear Schrödinger–Maxwell–Bloch equations are studied for the ultrashort pulse propagation in erbium-doped birefringent fiber system. Lax pair is constructed for the CHNLS–MB system. Through the Darboux method and symbolic computation, analytic two-soliton solution is obtained. To analyze the specific problem, we design an optimal system by properly choosing the special form of variable coefficients. Here, using obtained two-soliton solution, tunneling of femtosecond soliton through barrier and well is investigated. While solitons are passing through barrier and well, some unexpected behavior is observed and hidden possibilities in switching action through tunneling is investigated. [ABSTRACT FROM PUBLISHER]

In this paper, we develop a complete energy matrices approach investigating the defect structure and EPR parameters ( , , and ) for Er3+ in molybdates. In this approach, the crystal-field parameters used in the calculations are determined from the superposition model and the structural data for tetragonal distortion. The local distortion angles Δθ = −1.628°, Δθ = −1.843° and Δθ = −2.874° are obtained for Er3+ in SrMoO4, PbMoO4 and CaMoO4 crystals, respectively. Moreover, the influence of the orbital reduction factor k and the local distortion angle Δθ on the EPR parameters is analyzed. [ABSTRACT FROM PUBLISHER]

In this paper a tunable single-longitudinal mode (SLM), short-wavelength band (S-band) fiber laser using a conventional erbium-doped fiber (EDF) with a length of 3 m and a step index erbium dopant profile as opposed to the commonly used depressed cladding erbium-doped fiber (DC-EDF) is proposed and demonstrated. The proposed SLM fiber laser has a tuning range of 1496 to 1507 nm in a ring configuration using two 0.15 m of EDF which acts as saturable absorbers (SAs). The highest peak power measured is about −0.6 dBm at a wavelength range of 1502 to 1507 nm. The measured signal-to-noise ratio (SNR) is approximately 74 dB for the same wavelength range. The line-width of the SLM output is measured to be 140 kHz. [ABSTRACT FROM PUBLISHER]

Erbia-credit super high burnup (Er-SHB) fuel offers a means to introduce >5 wt% 235U enrichment fuel; small amounts of erbia added to all the high-enriched U02 powder can reduce the initial reactivity to <5 wt% enrichment level. By using this erbia credit, the new fuel can be treated as <5 wt% enriched fuel, and most modifications to the existing facilities and equipment can be avoided. One of the key issues for developing the Er-SHB fuel is to validate the criticality safety analysis tools for this fuel based on a series of experiments using fuel with small amounts of erbia in the entire core. For that purpose, a series of critical experiments have been performed at the Kyoto University Critical Assembly (KUCA). Four critical cores were constructed utilizing two different average enrichments, three different erbia contents, and four different H/U ratios. Numerical analyses have also been performed using several different cross-section libraries, and the results were compared with the measurements from the KUCA experiments. These results confirm the validity of the calculations and the cross-section libraries for determining erbia reactivity. This paper outlines the basic concepts of the Er-SHB fuel, the erbia experiments, and the analyses results. [ABSTRACT FROM AUTHOR]

In this paper, we propose and demonstrate a cost-effective wavelength converter utilising a highly nonlinear fibre (HNLF) and a tunable dual-wavelength fibre laser as the pump source. The proposed system uses only the pump source and a signal probe to generate a partially degenerate four-wave mixing (FWM) effect. An FWM conversion efficiency of -12 dB is obtained at pump and signal powers at +13.3 dBm and +5 dBm, respectively, and it is predicted that a higher conversion efficiency is possible if a high power dual-wavelength fibre laser source is used. [ABSTRACT FROM AUTHOR]

IRIS is a 335-MW(electric) pressurized water reactor (PWR) with integral primary system. Its design and optimized maintenance are compatible with long cycles, up to 4 yr. Advanced fuel management techniques are employed to support this objective; among others, novel use of burnable absorbers is considered. Erbium is one absorber that is currently utilized in PWRs. It has many desirable properties that ideally suit the extended cycle and low soluble boron concentration targeted by IRIS. However, erbium also leads to a cycle length penalty due to incomplete depletion and residual absorber isotopes, plus uranium displacement following erbium incorporation in the fuel matrix. This paper proposes to consider modifying the isotopic composition of erbium, evaluates its impact, and demonstrates that it is possible to obtain a considerable reduction of the penalty while retaining the positive features of natural erbium fuel. The economic benefit of the reduced penalty is appealing for the industrial production of isotopically modified erbium fuel. [ABSTRACT FROM AUTHOR]

The Er-doped YAB (YAl 3 (BO 3 ) 4 ) is a potential self-frequency-doubling laser material. Single crystals were grown by the top-seeded flux method. The absorption spectra of the infrared Er 3+ transitions were monitored in YAB crystals in the 9-300 K temperature range by high-resolution Fourier transform spectroscopy. In the whole spectral range the energy levels and Stark components of 12 transitions were detectable. In this paper the two infrared transitions (from the 4 I 15/2 ground state to the 4 I 13/2 and 4 I 11/2 levels) were analyzed in detail. The low temperature absorption spectra of Er:YAB consist of sharp lines, the number of which corresponds to the theoretical predictions. This suggests that Er 3+ ions occupy one specific lattice site (yttrium positions) with negligible aggregation at the higher dopant concentrations investigated ( i.e. 0.12 Er atom/YAB mole). [ABSTRACT FROM AUTHOR]

We investigate in this paper the influence of intensity-dependent losses on the dynamics of an erbium-doped fibre laser. On the basis of the ion-pair model, it is theoretically demonstrated that this feedback efficiently suppresses the self-pulsing occurring in heavily doped fibre lasers. [ABSTRACT FROM AUTHOR]