Showing papers on "Erbium published in 2017"
TL;DR: In this article, a nonlinear optical loop mirror with all polarization-maintaining fibers is used for robust mode-locked femtosecond (F2F) fiber laser.
Abstract: We report on a novel architecture for robust mode-locked femtosecond fiber lasers using a nonlinear optical loop mirror with all polarization-maintaining fibers. Due to a nonreciprocal phase shift, the loop mirror can be operated in a compact and efficient reflection mode, offering the possibility to reach high repetition rates and easy implementation of tuning elements. In particular, longitudinal mode spacing and carrier-envelope offset frequency may be controlled in order to operate the laser as an optical frequency comb. We demonstrate femtosecond pulse generation at three different wavelengths (1030, 1565, and 2050 nm) using Ytterbium, Erbium, and co-doped Thulium–Holmium as gain media, respectively. Robust operation is achieved for a wide range of parameters, including repetition rates from 10 to 250 MHz.
205 citations
TL;DR: The infrared part of the supercontinuum spectra shifts progressively towards the mid-infrared, well beyond 2.6 µm, by increasing the width of the waveguides, which agrees well with theoretical modeling based on the generalized nonlinear Schrödinger equation.
Abstract: We demonstrate supercontinuum generation in stoichiometric silicon nitride (Si3N4 in SiO2) integrated optical waveguides, pumped at telecommunication wavelengths. The pump laser is a mode-locked erbium fiber laser at a wavelength of 1.56 µm with a pulse duration of 120 fs. With a waveguide-internal pulse energy of 1.4 nJ and a waveguide with 1.0 µm × 0.9 µm cross section, designed for anomalous dispersion across the 1500 nm telecommunication range, the output spectrum extends from the visible, at around 526 nm, up to the mid-infrared, at least to 2.6 µm, the instrumental limit of our detection. This output spans more than 2.2 octaves (454 THz at the −30 dB level). The measured output spectra agree well with theoretical modeling based on the generalized nonlinear Schrodinger equation. The infrared part of the supercontinuum spectra shifts progressively towards the mid-infrared, well beyond 2.6 µm, by increasing the width of the waveguides.
98 citations
TL;DR: In this article, a single-crystal erbium chloride silicate nanowire was used for signal enhancement and transmission experiments on a 1,530-nm single cell.
Abstract: Rare-earth optical materials with large optical gain are of great importance for a wide variety of applications in photonics and quantum information due to their long carrier lifetimes and quantum coherence times, especially in the realization of efficient lasers and amplifiers. Until now, such materials have achieved a gain of less than a few dB cm–1, rendering them unsuitable for applications in nanophotonic integrated circuits. Here, we report the results of the signal enhancement and transmission experiments on a single-crystal erbium chloride silicate nanowire. Our experiments demonstrate that a net material gain over 100 dB cm–1 at wavelengths around 1,530 nm is possible due to the nanowire's single-crystalline material quality and its high erbium concentration. Our results establish that such rare-earth-compound nanowires are a potentially important class of nanomaterials for a variety of applications including, for example, subwavelength-scale optical amplifiers and lasers for integrated nanophotonics, and quantum information. Erbium chloride silicate nanowire promises optical gain for nanophotonic circuits.
65 citations
TL;DR: To the best of the authors' knowledge, this is the first report of a holmium nanoparticle doped fiber laser as well as the highest efficiency and power output reported from an erbium nanoparticles doped Fiber laser.
Abstract: A nanoparticle (NP) doping technique was developed for fabricating erbium (Er)- and holmium (Ho)-doped silica-based optical fibers for high energy lasers. Slope efficiencies in excess of 74% were realized for Er NP doping in a single mode fiber based master oscillator power amplifier (MOPA) and 53% with multi-Watt-level output in a resonantly cladding-pumped power oscillator laser configuration based on a double-clad fiber. Cores comprising Ho doped LaF3 and Lu2O3 nanoparticles exhibited slope efficiencies as high as 85% at 2.09 µm in a laser configuration. To the best of the authors’ knowledge, this is the first report of a holmium nanoparticle doped fiber laser as well as the highest efficiency and power output reported from an erbium nanoparticle doped fiber laser.
63 citations
TL;DR: In this paper, a simple Q-switched Erbium-doped fiber (EDF) and Ytterbium doped fibre (YDF) was fabricated by using topological insulator (TI) Bismuth Selenide (Bi2Se3) as saturable absorber.
Abstract: This paper portrays a simple Q-switched Erbium-doped fibre (EDF) and Ytterbium doped fibre (YDF) lasers by using topological insulator (TI) Bismuth Selenide (Bi2Se3) as saturable absorber. The modulation depth of the fabricated Bi2Se3 is about 39.8% while its saturating intensity is about 90.2 MW/cm2. By depositing the TI Bi2Se3 SA onto fibre ferrules and incorporate it inside the proposed cavity, a stable Q-switching operation was achieved at 1 μm and 1.5 μm. The fabricated Bismuth Selenide (Bi2Se3) as saturable absorber (SA) is a broadband SA where it offers a compact and low cost fabrication which is beneficial in various photonic applications.
58 citations
TL;DR: In this article, a broadband optical amplifier operating in the wavelength range from 1515 to 1775 nm has been realized using the developed bismuth and erbium-codoped fibers.
Abstract: Bi- and Er-codoped germanosilicate optical fibers have been fabricated and studied as a potential gain medium for fiber-based devices operating in the near infrared region. A broadband optical amplifier operating in the wavelength range from 1515 to 1775 nm has been realized using the developed bismuth- and erbium-codoped fibers. The 15 dB small-signal gain band covers 260 nm when pumped by a laser diode at 1460 nm with an output power of 350 mW.
45 citations
TL;DR: In this article, a 32c-MC-EYDFA with a side pumping technique is employed for ease of pump coupling in this monolithic all-fiber amplifier, achieving a minimum gain of >17 dB and an average noise figure (NF) of 6.5 dB.
Abstract: We present a high-core-count 32-core multicore erbium/ytterbium-doped fiber amplifier (32c-MC-EYDFA) in a cladding pumped configuration. A side pumping technique is employed for ease of pump coupling in this monolithic all-fiber amplifier. A minimum gain of >17 dB and an average noise figure (NF) of 6.5 dB is obtained over all cores in the wavelength range 1534 nm-1561 nm for −4 dBm input signal power. The core-to-core variation for both amplifier gain and NF is measured to be 1850 km was successfully demonstrated. We also compare the total power consumption of our MC-EYDFAs with that of 32 conventional single core erbium doped fiber amplifiers (EDFAs) to illustrate the potential power saving benefits.
45 citations
TL;DR: In this paper, a Raman laser with a wavelength exceeding 4 μm was designed for the first time using a revolver silica fibre with a hollow core filled with molecular hydrogen (1H2) as an active medium.
Abstract: A Raman laser with a wavelength exceeding 4 μm is designed for the first time. Using a revolver silica fibre with a hollow core filled with molecular hydrogen (1H2) as an active medium, we have obtained SRS lasing at a wavelength of 4.4 μm under pumping by a pulsed erbium fibre laser (λ = 1.56 μm, τ = 2 ns). The SRS conversion quantum efficiency reaches 15 %, and the maximum output peak power at a wavelength of 4.4 μm is 0.6 kW.
45 citations
TL;DR: In this article, a glass series of erbium doped zinc borotellurite glass system was prepared by using the melt-quenching method and the absorption spectra revealed several bands at visible range.
45 citations
TL;DR: In this article, the authors demonstrate the nonlinear optical response of layered metal dichalcogenides (LMDs) that is exploited as a saturable absorber in the near and mid-infrared regions.
Abstract: Layered metal dichalcogenides (LMDs) have received considerable attention in optoelectronics and photonics. Tin disulfide (SnS2) as a member of the LMDs has been employed for transistors, energy storage, and photocatalysts. The optical properties of SnS2 in the ultraviolet and visible regions have been widely investigated, while the applications of SnS2 in the near- and mid-infrared regions are still rare. Here, we demonstrate the nonlinear optical response of layered SnS2 that is exploited as a saturable absorber in the near- and mid-infrared regions. The saturable absorption of SnS2 is measured at 1.06 and 1.55 μm, which illustrates a low saturable intensity. SnS2 covered on a D-shaped fiber is used to initiate the mode-locking operations in erbium-, ytterbium-, and thulium-doped fiber lasers and ultrafast pulses are achieved at 1.03, 1.56, and 1.91 μm. These results make SnS2 an appealing candidate for broadband applications across the near- and mid-infrared regions.
44 citations
TL;DR: The effective atomic numbers and electron densities for the pure elemental forms of gadolinium (Gd), dysprosium (Dy), erbium (Er), and ytterbium(Yb), and some of their selected complexes, were obt...
Abstract: The effective atomic numbers and electron densities for the pure elemental forms of gadolinium (Gd), dysprosium (Dy), erbium (Er), and ytterbium (Yb), and some of their selected complexes, were obt...
TL;DR: A wide bandwidth and flat multiwavelength Brillouin-erbium fiber laser is demonstrated experimentally and the effect of four-wave mixing in highly nonlinear fiber increases the generation of BrillouIn Stokes lines in a wider bandwidth.
Abstract: A wide bandwidth and flat multiwavelength Brillouin-erbium fiber laser is demonstrated experimentally. In the proposed laser setup, the combination of a Brillouin mirror with feedback and a ring cavity with four-wave mixing assistance is realized. The efficiency of Brillouin Stokes lines generation is enhanced by the feedback-based Brillouin mirror structure. The effect of four-wave mixing in highly nonlinear fiber increases the generation of Brillouin Stokes lines in a wider bandwidth. The laser lines over 16 nm bandwidth (i.e 200 channels) within 4.65 dB power difference are obtained. The generated laser lines span from 1534 to 1550 nm with wavelength spacing of 0.08 nm and optical signal-to-noise ratio of at least 15 dB. The laser can also be freely tuned over 32 nm and is stable with power fluctuations of 0.7 dB over 1 hour duration.
TL;DR: This work generates over 60 mW of pulses with wavelengths from 6 to 11 micrometers by difference frequency mixing between erbium and thulium fiber amplifiers in orientation-patterned GaP with a photon conversion efficiency of 0.2.
Abstract: We generate over 60 mW of pulses with wavelengths from 6 to 11 micrometers by difference frequency mixing between erbium and thulium fiber amplifiers in orientation-patterned GaP with a photon conversion efficiency of 0.2. By stabilizing the repetition rate of the shared oscillator and adding a frequency shifter to one arm, the output becomes a frequency comb with tunable carrier envelope offset.
TL;DR: In this paper, a wavelength-tunable erbium-doped fiber (EDF) ring laser with stable single-longitudinal-mode (SLM) output was demonstrated.
Abstract: In this work, we demonstrate a wavelength-tunable erbium-doped fiber (EDF) ring laser with stable single-longitudinal-mode (SLM) output. Here using the self-injection method and unpumped EDF-based saturable absorber can suppress other densely side-mode to achieve SLM. Hence, the output power and optical signal-to-noise ratio of proposed EDF ring laser are between −7.1 and 2.1 dBm and 30.1 and 36.5 dB in the tuning range of 1525.0 to 1574.0 nm, respectively. According to the proposed EDF laser structure, the wavelength operation range can extend to shorter L-band from C-band. Moreover, the output stability of the proposed EDF ring laser is also executed experimentally.
TL;DR: A new hybrid platform is presented that integrates amorphous silicon photonic waveguides and microresonators fabricated on top of a yttrium orthosilicate substrate doped with erbium ions that exhibited spontaneous emission rate enhancement and increased coupling to the input field, as required for further development of on-chip quantum light-matter interfaces.
Abstract: A scalable platform for on-chip optical quantum networks will rely on standard top-down nanofabrication techniques and solid-state emitters with long coherence times. We present a new hybrid platform that integrates amorphous silicon photonic waveguides and microresonators fabricated on top of a yttrium orthosilicate substrate doped with erbium ions. The quality factor of one such resonator was measured to exceed 100,000 and the ensemble cooperativity was measured to be 0.54. The resonator-coupled ions exhibited spontaneous emission rate enhancement and increased coupling to the input field, as required for further development of on-chip quantum light-matter interfaces.
TL;DR: In this article, the influence of erbium doping on the optical and electrical properties of a Bi4Ti3O12 compound was studied, and it was found that the conductivity spectrum of the investigated materials obeys the Jonscher universal double power law.
Abstract: We have studied the influence of erbium doping on the optical and electrical properties of a Bi4Ti3O12 compound. Bi4−xErxTi3O12 (x = 0.0, 0.1, 0.2 and 0.3) samples are prepared by the solid state reaction method. X-ray diffraction (XRD) revealed that our samples are homogenous and crystallize in the orthorhombic system with the Fmmm space group. Absorbance measurement reveals that the peak intensity increases with increasing erbium concentrations and this behavior confirms the good homogeneity of the samples. DC-conductivity measurements show that all samples are characterized by a semiconductor behavior. It is found that electrical conductivity is reduced considerably with increasing erbium content up to x = 0.3. This is due to the decrease in oxygen vacancy density. For the free compound, dc-conductivity is characterized by the appearance of a saturation region at a specific temperature (Tsat = 480 K). For Er doped compounds, Tsat goes beyond 600 K. An AC-conductivity study shows that the conductivity is governed by the jump relaxation model (JRM) and conduction through grain boundaries. We found that the conductivity spectrum of the investigated materials obeys the Jonscher universal double power law. The deduced activation energy increases when increasing the erbium content from Ea = 467 meV for x = 0 to Ea = 670 meV for x = 0.3. Increasing the Er substitution reduces the frequency dispersion of the real part of the dielectric constant e′. Also, the tan δ plot indicates that the investigated samples exhibit the characteristics of a relaxor dielectric.
TL;DR: In this article, the design of a highly efficient integrated dual-mode interferometer with single-mode inputs and outputs and simple fabrication steps in a silicon-on-insulator platform with CMOS compatible technology is presented.
Abstract: The design of a highly efficient integrated dual-mode interferometer with single-mode inputs and outputs and simple fabrication steps in a silicon-on-insulator platform with CMOS compatible technology is presented. Consisting of only one waveguide and two special mode converters, the device offers high sensitivity and immunity to input power fluctuations and temperature changes. Special attention is paid to the design of low-loss mode converters with two single-mode outputs for total power tracking. Considerations on temperature influence, fabrication tolerances, and dual mode waveguide sensitivity conclude the theoretical part. Experimental results of a single-port dual-mode interferometer show extinction ratios up to 31 dB and insertion losses of less than 1 dB at a wavelength of 1550 nm. With an additional functional polymer layer, the selective detection of various concentrations of L-Boc-phenylalanine anilid in an ethanol-water solution is demonstrated.
TL;DR: The mechanism of BAC-Si bleaching linked to an escaping excited electron is further confirmed with both photo-bleaching experiments by different laser pump wavelengths and a potential energy model describing the loss of an excited electron.
Abstract: Photo-bleaching of the silica-related bismuth active center (BAC-Si) in bismuth/erbium co-doped optical fibers is investigated. By analyzing dynamic spectral characteristics of BAC-Si, the photo-bleaching of the BAC-Si is found to be linked to the escape of an excited electron from the bismuth site in the BAC-Si. This mechanism of BAC-Si bleaching linked to an escaping excited electron is further confirmed with both photo-bleaching experiments by different laser pump wavelengths and a potential energy model describing the loss of an excited electron. Additionally, the temperature effect on the photo-bleaching, which is in good agreement with the above findings, is observed and discussed.
TL;DR: In this article, a Co3O4 nanocubes are embedded into a polyethylene oxide film to produce a high nonlinear optical response, which is useful for SA application.
Abstract: We demonstrate a Q-switched Erbium-doped fibre laser (EDFL) utilizing cobalt oxide (Co3O4) nanocubes film based saturable absorber (SA) as a passive Q-switcher. Co3O4 nanocubes are embedded into a polyethylene oxide film to produce a high nonlinear optical response, which is useful for SA application. It has saturation intensity and modulation depth of 3 MW/cm2 and 0.35%, respectively. The proposed laser cavity successfully generates a stable pulse train where the pulse repetition rate is tunable from 29.8 to 70.92 kHz and the pulse-width reduces from 10.9 to 5.02 μs as the 980 nm pump power increases. This result indicates that the Co3O4 is excellent for constructing an SA that can be used in producing a passively Q-switched fibre laser operating at a low pump intensity. To the best of our knowledge, this is the first demonstration of Co3O4 film based fibre laser.
TL;DR: In this paper, the physical, structural and optical properties are explained by analysing the data obtained from Energy Dispersive X-ray Fluorescence (EDXRF), density (ρ), molar volume (V m), Xray diffraction (XRD), fourier transform infra-red (FTIR) and UV-visible (UV-Vis) results.
Abstract: Erbium doped ZnO–SLS (soda lime silica) glass system have been prepared by the conventional melt quenching technique. The physical, structural and optical properties are explained by analysing the data obtained from Energy Dispersive X-ray Fluorescence (EDXRF), density (ρ), molar volume (V m), X-ray diffraction (XRD), fourier transform infra-red (FTIR) and UV-visible (UV-Vis) results. The measured physical parameters like density and molar volume are found to vary linearly and exponentially with increasing Er2O3 content, respectively. X-ray powder diffractrogram show broad peaks which conforms glassy nature of the sample. FTIR spectroscopy reveals the presence of SiO4, ZnO4 and Er–O vibration groups in the glass samples. The optical absorption spectra were measured in the wavelength range from 300 to 800 nm and the optical band gaps were determined. The optical absorption spectra of Er3+ ions in these glasses show three bands and are assigned to the transitions level. It was found that the optical band gap decreases from 3.083 to 3.037 eV with an increase in Er2O3 concentration.
TL;DR: In this article, the optical properties of two glass series (a-ordinary glass, b-glass with nanoparticles) have been compared by using TEM, EDX and XRD.
Abstract: Comparative analysis on optical properties between two glass series (a—ordinary glass, b—glass with nanoparticles) have been estimated. The two glass series (a—ordinary glass, b—glass with nanoparticles) with compositions {[(TeO2)0.70 (B2O3)0.30]0.70 (ZnO)0.30}1−y (Er2O3/Er2O3 nanoparticles)y; y = 0.005, 0.01, 0.02, 0.03, 0.04, 0.05 mol% were successfully prepared by using melt-quenching method. The TEM, EDX and XRD have been used to confirm the existence of nanoparticles and all elements in the glass system. The density of b—glass with nanoparticles are found greater than a—ordinary glass. The optical properties of the glass series were characterized by using Ellipsometer and UV–Vis spectrophotometer. There is a linear increasing trend in refractive index of the glass series along with concentration of erbium and erbium nanoparticles oxide. The refractive index of b—glass with nanoparticles is greater than a—ordinary glass. Moreover, the absorption peaks of a—ordinary glass are more intense than b—glass with nanoparticles. The glass with nanoparticles will offer a potential materials for nanophotonic devices.
TL;DR: In this paper, various Er/β-zeolite catalysts were prepared by grafting erbium species in aqueous solutions of erbinium chloride onto β-zeolis, and they were evaluated in the one-pot cellulose to lactic acid conversion.
Abstract: Various Er/β-zeolite catalysts were prepared by grafting erbium species in aqueous solutions of erbium chloride onto β-zeolites. The catalysts were characterized using X-ray fluorescence spectroscopy, inductively coupled plasma optical emission spectroscopy, N2 physical adsorption, powder X-ray diffraction, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, and NH3 temperature-programmed desorption. These catalysts were evaluated in the one-pot hydrothermal conversion of cellulose to lactic acid. Lactic acid yields of approximately 58 % were obtained using an erbium grafted on de-aluminated β zeolite (Er/deAlβ-2) with an erbium content of 12.4 wt% and a Si/Al ratio of 159:1. In catalyst recycling tests, the lactic acid yield decreased from 57.9 % in the first cycle to 51.2, 49.8 and 49.6 % in the second, third and fourth cycles, respectively. The decreases in catalytic activity during recycling are proposed to arise mainly from a combination of erbium ion leaching, deposition of carbon species in the zeolite pores and the partial structure collapse.
TL;DR: Results of high average power mid-infrared (mid-IR) generation employing synchronized nanosecond pulsed ytterbium and erbium fiber amplifier systems using periodically poled lithium niobate are presented.
Abstract: We present results of high average power mid-infrared (mid-IR) generation employing synchronized nanosecond pulsed ytterbium and erbium fiber amplifier systems using periodically poled lithium niobate. We generate greater than 6 W of mid-IR radiation tunable in wavelength between 3.31–3.48 μm, at power conversion efficiencies exceeding 75%, with near diffraction limited beam quality (M2 = 1.4). Numerical modeling is used to verify the experimental results in differing pump depletion regimes.
TL;DR: In this article, a curved erbium doped aluminum oxide (Al2O3:Er3+) distributed feedback (DFB) laser was proposed for a reliable integrated photonics light source.
Abstract: We propose a curved erbium doped aluminum oxide (Al2O3:Er3+) distributed feedback (DFB) laser for a reliable integrated photonics light source. The curved structure allows us for compensation of the radially varying film thickness due to the Al2O3:Er3+ deposition process. In a conventional straight DFB structure, we observe randomly distorted transmission responses and relatively higher threshold power even for an estimated 6 times lower threshold compared to the straight DFB laser.
TL;DR: Erbium-doped titanium in-diffused ridge waveguide optical amplifiers in x-cut congruent LiNbO3 substrates pumped by a 1486-nm laser diode are reported for the first time in this paper.
Abstract: Erbium-doped titanium in-diffused ridge waveguide optical amplifiers in x-cut congruent LiNbO3 substrates pumped by a 1486 nm laser diode are reported for the first time. High internal gain of 2.7 dB/cm has been demonstrated in 2.5 cm long waveguides for the coupled pump power 200 mW exceeding the best literature values reported for Er:Ti:LiNbO3 channel waveguides. For gain improvement, we have developed a novel technique which is comprised of ridge definition using diamond blade dicing followed by three-side erbium (Er) and titanium (Ti) layer deposition and high-temperature diffusion. Thereby both higher Er concentrations with more symmetric diffusion profiles and lower scattering losses due to the high-temperature smoothened waveguide side walls have been obtained.
TL;DR: The spectral width is the narrowest among all-fiber passively mode locked Erbium-doped laser based on NPR, and can be readily extended to other wavelength such as mid-infrared (mid-IR) where fiber polarizing components are either expensive or not available.
Abstract: An all-fiber passively picosecond mode locked Erbium doped laser using a 45° tilted fiber grating (45° TFG) and a fiber Bragg grating (FBG) is reported in this work. Due to the strong polarization dependent loss (PDL) of 45° TFG and narrow 3-dB bandwidth of FBG, the Erbium doped fiber laser (EDFL) can generate picosecond mode locked pulse based on the nonlinear polarization rotation (NPR) effect. The laser features a repetition rate of 9.67 MHz, a pulse duration of 33 ps, a signal-to-noise ratio (SNR) of 70 dB, an average output power of 1.2 mW, and a single pulse energy of 124 pJ under the pump power of 102 mW. Besides, the central wavelength of the laser can be continuously adjusted from 1550.65 nm to 1551.44 nm. The technique of using a 45° TFG to generate picosecond pulses can be readily extended to other wavelength such as mid-infrared (mid-IR) where fiber polarizing components are either expensive or not available. To the best of our knowledge, the spectral width is the narrowest among all-fiber passively mode locked Erbium-doped laser based on NPR
TL;DR: The authors generalizes the generator coordinate method to include deformation parameters together with two-quasiparticle excitations, and the results agree well with the experimental data for erbium isotopes ranging from very soft to very rigid shapes.
Abstract: This work generalizes the generator coordinate method to include ($\ensuremath{\beta}$,$\ensuremath{\gamma}$) deformation parameters together with two-quasiparticle excitations. The simultaneous consideration of collective as well as single particle degrees of freedom allows one to describe soft and rigid nuclei as well as the transition region in between. The results agree well with the experimental data for erbium isotopes ranging from very soft to very rigid shapes.
TL;DR: The concept of smart doping via material nanostructuring as a way to fabricate more efficient optical devices is investigated by optimizing the glass composition of the fiber core in order to use the minimal content of glass modifiers needed to reach the suited level of performances for EDFA.
Abstract: Erbium-doped fiber amplifiers (EDFAs) for harsh environments require to develop specific fabrication methods of Er 3+-doped fibers (EDFs) so as to limit the impact of radiation-induced absorption. In this context, a compromise has to be found between the concentration of Erbium and the glass composition. On the one hand, high concentration of Er 3+ ions helps to reduce the length of the EDF and hence the cumulated attenuation but generally leads to luminescence quenching mechanisms that limit the performances. On the other hand, so as to avoid such quenching effect, glass modifiers like Al 3+ or P 5+ ions are used in the fabrication of commercial EDFs but are not suitable for applications in harsh environment because these glass modifiers are precursors of radiation-induced structural defects and consequently of optical losses. In this work, we investigate the concept of smart doping via material nanostructuring as a way to fabricate more efficient optical devices. This approach aims at optimizing the glass composition of the fiber core in order to use the minimal content of glass modifiers needed to reach the suited level of performances for EDFA. Er 3+-doped alumina nanoparticles (NPs), as precursor of Er 3+ ions in the preform fabrication process, were used to control the environment of rare-earth ions and their optical properties. Structural and optical characterizations of NP-doped preforms and optical fibers drawn from such preforms demonstrate the interest of this approach for small concentrations of aluminum in comparison to similar glass compositions obtained by a conventional technique.
TL;DR: In this paper, a dual 830 and 980 nm pumping scheme was proposed aiming at broadening and flattening the spectral performance of bismuth/erbium codoped multicomponent fiber (BEDF).
Abstract: A dual 830 and 980 nm pumping scheme is proposed aiming at broadening and flattening the spectral performance of bismuth/erbium codoped multicomponent fiber (BEDF). The spectral properties of distinct Bi active centers (BACs) associated with germanium (BAC-Ge), aluminium (BAC-Al), phosphorus (BAC-P) and silicon (BAC-Si) are characterized under single pumping of 830 and 980 nm, respectively. Based on the emission slope efficiencies of BAC-Al (∼1100 nm) and BAC-Si (∼1430 nm) under single pumping of 830 and 980 nm, the dual pumping scheme with the optimal pump power ratio of 25 (980 nm VS 830 nm) is determined to achieve flat, ultrabroadband luminescence spectra covering the wavelength range 950-1600 nm. The dual pumping scheme is further demonstrated on the on-off gain performance of BEDF. It is found under the pump power ratio of ∼8 (980 VS 830 nm), The gain spectrum has been flattened and broadened over 300 nm (1300-1600 nm) with an average gain coefficient of ∼1.5 dBm-1. The spectral coverage is approxim...
TL;DR: In this article, a topology optimization study of metal nanostructures optimized for electric-field enhancement in the infrared spectrum is presented, where the infrared absorption band of erbium is utilized by simultaneously optimizing for two polarizations, up to three wavelengths, and three incident angles.
Abstract: This letter presents a topology optimization study of metal nanostructures optimized for electric-field enhancement in the infrared spectrum. Coupling of such nanostructures with suitable ions allows for an increased photon-upconversion yield, with one application being an increased solar-cell efficiency by exploiting the long-wavelength part of the solar spectrum. In this work, topology optimization is used to design a periodic array of two-dimensional gold nanostrips for electric-field enhancements in a thin film doped with upconverting erbium ions. The infrared absorption band of erbium is utilized by simultaneously optimizing for two polarizations, up to three wavelengths, and three incident angles. Geometric robustness towards manufacturing variations is implemented considering three different design realizations simultaneously in the optimization. The polarization-averaged field enhancement for each design is evaluated over an 80 nm wavelength range and a ±15-degree incident angle span. The highest ...