Erbium Doped Research Articles

The Role of Saturable Absorbers Thickness in the Q-Switching of Erbium Doped Fiber Laser

The Role of Saturable Absorbers Thickness in the Q-Switching of Erbium Doped Fiber Laser

Substantially Enhanced Properties of 2D WS2 by High Concentration of Erbium Doping against Tungsten Vacancy Formation.

Doping in 2D materials is an important method for tuning of band structures. For this purpose, it is important to develop controllable doping techniques. Here, we demonstrate a substitutional doping strategy by erbium (Er) ions in the synthesis of monolayer WS2 by chemical vapor deposition. Substantial enhancements in photoluminescent and photoresponsive properties are achieved, which indicate a tungsten vacancy suppression mechanism by Er filling. Er ion doping in the monolayer WS2 is proved by X-ray diffraction (XRD) and X-ray photoelectron spectra (XPS), fluorescence, absorption, excitation, and Raman spectra. 11.5 at% of the maximum Er concentration is examined by energy dispersive X-ray spectroscopy (EDX). Over 6 times enhancement of intensities with 7.9 nm redshift in peaks are observed from the fluorescent spectra of Er-doped WS2 monolayers compared with their counterparts of the pristine WS2 monolayers, which agrees well with the density functional theory calculations. In addition, over 11 times of dark current, 469 times of photocurrents, photoresponsivity, and external quantum efficiency, and two orders of photoresponse speed are demonstrated from the Er-doped WS2 photodetector compared with those of the pristine WS2 device. Our findings prove rare-earth doping in 2D materials, the exciting and ideal technique for substantially enhanced photoluminescent and photoresponsive properties.

Influence of erbium (Er) dopant on the enhanced optical properties of electrochemically deposited zinc oxide (ZnO) films for high-performance photovoltaic systems

Undoped and Er doped ZnO thin film materials have been successfully synthesized using the electrochemically deposited (ECD) technique. SEM results of the undoped and Er/ZnO (at 0.1, 0.2, 0.3 mol%) thin-film materials deposited on FTO substrate reveal the presence of crystallite of various sizes. The morphological and structural properties of the films were investigated using SEM and XRD techniques. XRD results of all the films show peaks at crystal plane (100), (111), and (112) with a prominent preferred orientation along the (100) plane. The optical energy band gap of ZnO was observed to decrease from 1.32 eV to 1.25 eV as a result of the addition of Er as the dopant. The absorbance of undoped and Er/ZnO (at 0.1, 0.2, 0.3 mol%) reveals that all thin-film materials exhibited high absorbance values in the UV–Vis region which dropped drastically as they move towards the NIR region. It was observed that the incorporation of Er in the undoped ZnO led to a notable rise in the absorbance value which indicates that Er doping greatly improved the light absorption of the ZnO thereby making it a good photovoltaic material.

Influence of erbium doping on zinc oxide nanoparticles: Structural, optical and antimicrobial activity

Antimicrobial activity of the Zn1-xErxO (0, 1, 5, 10 at.%) nanoparticles were tested against Staphylococcus aureus and Escherichia coli. The nanoparticles were successfully synthesized by wet chemical route, where polyvinyl alcohol and sucrose were used. The influence of erbium content in structural, optical, and antimicrobial activity was analyzed. The average crystallite size is under 15 nm for all the samples according to X-ray diffraction results, and no secondary phases were observed even at high erbium content. Optical results exhibit a blue shift in the ultra-violet region. The X-ray photoelectron spectroscopy analysis confirmed the variations of Zn/O ratio, together with particles size and band gap are key factor in antimicrobial properties. The microbiological essays exhibit to these nanoparticles as a high potential agent with antibacterial activity versus S. aureus, with lower impact in E. coli. The absorbance results of these assays were used in two theoretical approaches. At first, Gompertz model used in the regression analysis showed the best fit for bacterial growth. Additionally, an artificial neural network was trained to forecast the result of new experiments, showing a good performance.

Multifunctional and smart Er2O3-ZnO nanocomposites for electronic ceramic varistors and visible light degradation of wastewater treatment.

In this proposed study, erbium (Er3+)-doped ZnO nanocomposites were prepared through the effective, basic, and green combustion method. The significant effects of Er dopants on the structural, morphological features, dielectric, and optical behaviors of the pure ZnO matrix as well as Er2O3-ZnO nanostructured materials were investigated applying X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transformation infrared (FT-IR) spectroscopy, and UV-Vis spectrophotometer techniques. These results showed that the synthesized Er2O3-ZnO nanocomposites are well polycrystalline. The Er2O3-ZnO nanocomposites are almost uniformly distributed on the surface morphologies. Furthermore, UV-Vis diffuse reflectance spectroscopy, AC electrical conductivity, and dielectric properties' current-voltage characteristics were utilized to examine the influence of erbium doping on the optical properties, energy bandgaps of the proposed Er2O3-ZnO nanostructured powder. The tested nano-samples were applied for the visible light photodegradation of p-chlorophenol(4-CP) and p-nitrophenol (4-NP). The Er-doped ZnO ratio affects the photocatalytic activity of the ZnO matrix. This current research substantiated that more than 99.5% of 4-CP and 4-NP were photodegraded through 30 min of irradiation. Four times, the Er:ZnO nanocatalysts were used and still displayed an efficiency of more than 96.5% for 4-CP and 4-NP degradations in the specified period of 30 min. The as-prepared Er2O3-ZnO nanostructures are considered novel potential candidates in broad nano-applications from visible photocatalytic degradation of waste pollutants to the electronic varistor devices.

Statistical dependence analysis of Erbium doped fiber ring lasers (EDFRL) chaos

Utilizing ergodic nature of chaotic lasers, the probability density function (PDF) estimation is carried out for peak amplitudes of pulsed chaos in Erbium Doped Fiber Ring Laser (EDFRL) in relation to varying the four key cavity parameters i.e. cavity gain, pump power, modulation index and modulation frequency. Kernel based non-parametric probability distributions are found more suitable to fit the chaos peaks data instead of parametric Gaussian, Rayleigh or Poisson Probability Density Functions. The resulting non-parametric PDFs’ shape, modes, skew and variance is found controllable by changing cavity parameters which is beneficial for random number generation with desired properties. The non-parametric distribution changed its shape between uni-modal and bimodal Gaussian like PDFs alternately and the variance also changes. The PDF shape corresponds to density of points in chaotic data bifurcation plots. This statistical in depth analysis is important while employing the EDFRL for random number generation and in chaotic secure communication applications. EDFRL chaos is found here to be a non-Poisson doubly stochastic point process implying it does depend on history of the chaos generation process, which is hidden in the slowly varying population inversion density of the laser. The bimodality skew keeps altering between left and right while becoming uni-modal every time between switching with modulation index and pump power changes. At high gain the variance of PDF decreases and it approaches uni-modal Gaussian. At high modulation frequency the PDF is left skewed with higher number of shorter pulses bursting.

Metasurface‐Enhanced Photon Upconversion upon 1550 nm Excitation

AbstractPhoton upconversion upon 1550 nm excitation is of high relevance for applications in the third biological excitation window, for photovoltaics beyond current limitations, and enables appealing options in the field of glass fiber telecommunications. Trivalent doped erbium ions (Er3+) are the material of choice for 1550 nm excited upconversion, however, they suffer from a low absorption cross‐section and a low brightness. Therefore, the ability of silicon metasurfaces to provide greatly enhanced electrical near‐fields is employed to enable efficient photon upconversion even at low external illumination conditions. Hexagonally shaped β‐NaYF4:Er3+ nanoparticles are placed on large‐area silicon metasurfaces designed to convert near‐infrared (1550 nm) to visible light. More than 2400‐fold enhanced photon upconversion luminescence is achieved by using this metasurface instead of a planar substrate. With the aid of optical simulations based on the finite‐element method, this result is attributed to the coupling of the excitation source with metasurface resonances at appropriate incident angles. Analysis of the excitation power density dependence of upconversion luminescence and red‐to‐green‐emission ratios enables the estimation of nanoscale near‐field enhancement on the metasurface. The findings permit the significant reduction of required external excitation intensities for photon upconversion of 1550 nm light, opening perspectives in biophotonics, telecommunication, and photovoltaics.

Judd-Ofelt analysis and luminescence studies of Er3+ doped halogeno-antimonate glasses

This research paper emphasized on application of Judd-Ofelt's (JO) theory for low doped erbium (0.2 mol%) halogeno-antimonate based glasses with molar composition (90 –x) Sb 2 O 3 - x ZnBr 2 - 10 NaCl (where x = 10, 20, 30 and 40 mol%). 80 Sb 2 O 3 – 9.8 ZnBr 2 - 10 NaCl - 0.2 Er 2 O 3 glass sample has low phonon energy and high refractive index is a potential candidate for luminescence applications. Differential scanning calorimetry (DSC) measurements show good the thermal stability of the prepared glass samples and on the other hand density, expansion coefficient and elastic moduli were reported. Judd-Ofelt's (JO) parameter intensities Ω 2 = 3.27 × 10 −20 cm 2 , Ω 4 = 1.24 × 10 −20 cm 2 and Ω 6 = 1.88 × 10 −20 cm 2 were found and these were compared with the literature. Radiative parameters such as spontaneous emission rate, branching ratio and lifetime were calculated. We focused on a high branching ratio radiative transitions 2 H 11/2 → 4 I 15/2 (β = 0.94) and 4 F 9/2 → 4 I 15/2 (β = 0.901). The overlap between absorption and emission bands is partial and stokes type shifts were presented. The gain curves were determined after calculation of absorption and stimulated emission cross sections. The infrared transmission curve of the glass matrix was marked extrinsic absorption bands SiO and hydroxyl OH possessed high vibration energy played quenching effect for photoluminescence. • SZNE02 novel glass system was developed by the conventional melt quenching method. • Judd-Ofelt's (JO) parameter intensities were compared with the literature. • High branching ratio radiative transitions. • Optical gap energy (E p = 2.95 eV) and refractive index n = 2.25 • Stimulated emission gains as a function of wavelength for different states of population inversion.

Rigorous FM-EDF design with an oversized two-layer erbium ion distribution for C-band DMG mitigation

We present a rigorous design of few-mode erbium doping fiber (FM-EDF) with an oversized two-layer erbium ion distribution at the central region with effective differential modal gain (DMG) mitigation over the C-band. The proposed erbium doping distribution allows for a similar overlapping integral value among the guided modes, leading to a signal gain equalization over the C-band. When the length of the proposed FM-EDF is 8 m under the cladding pumping power of 2.5 W, our calculated results reveal that four linearly polarized (LP)-modes can achieve an average gain per mode of 24.8 dB and a typical DMG of less than 0.64 dB over the C-band. Meanwhile, we carry out numerical simulations to explore the fabrication tolerance of the oversized two-layer erbium doping distribution with respect to the DMG, indicating stable DMG mitigation over the C-band. We believe that such new manipulation of erbium doping distribution is helpful for the multiple-dimensional multiplexing of fiber optical transmission.

Effect of erbium doping on phase composition, mechanical and thermal properties of ZrO2-based ceramics

ErxTi0.1Zr0.9–xO2–1.5x (x = 0.04, 0.05, 0.06, 0.07, 0.08) ceramics were synthesized by a solid-state reaction method. The influence of the Er3+ addition on the phase composition, Vickers hardness, fracture toughness, and thermal conductivity of this ceramic material was investigated. The X-ray diffraction results reveal that the c-ZrO2 content increases from 1.85 vol% to 33.89 vol%, and the percentage of t-ZrO2 decreases from 98.15 vol% to 66.11 vol% with the increase in Er3+ content from 4 mol% to 8 mol%. Moreover, the addition of Er3+ is beneficial to the volume expansion of the unit cell. At the same time, the incorporation of Er3+ weakens the coordination of oxygen ions around the metal cations, resulting in a corresponding decrease in the tetragonality of the t-ZrO2. The Vickers hardness and fracture toughness of the ErxTi0.1Zr0.9–xO2–1.5x ceramics show increasing and decreasing trends, respectively. The thermal conductivity has a significant decline due to point defects caused by the Er3+ doping. The 8ETZ ceramic exhibits the highest Vickers hardness (12.7 GPa), the lowest fracture toughness (7.6 MPa⋅m1/2), and the lowest average thermal conductivity (1.85 W/(m·K)) in the temperature range of 200–1000 °C. All of the above properties are higher than those of the Y2O3-stabilized ZrO2 ceramic.

High performance of Er-doped Sb2Te material used in phase change memory

To date, operation speed and data retention are still bottlenecks for phase-change memory. Doping impurity is a practical strategy to improve these performances of phase-change memory. Here, to avoid the precipitation of impurity, we choose erbium (Er) dopant due to the most matched structure with parental Sb2Te (EST), which is manifested by both experimental and simulation results that Er locates at lattice position. The device tests show the excellent comprehensive performances: operation speed as fast as 6 ns and 10-year data retention as high as 121 °C. This excellent amorphous thermal stability stems from the strong ErTe bonds, and these stable local patterns stabilize glassy states and result in high stability. Our study not only demonstrates that the performance of designed EST meets the requirement of phase-change memory, but also provides general doping rules to obtain better comprehensive performance.

Design of Ring-Core Few-Mode-EDFA With the Enhanced Saturation Input Signal Power and Low Differential Modal Gain

We propose a design of ring-core few-mode fiber (RC-FMF) with the erbium doping at the cladding region near the outer ring edge. After the parameter optimization of the RC-FM-EDF, the intensity overlapping difference between LP <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">01</sub> and LP <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sub> modes can be minimized, leading to a DMG of 0.22 dB for the corresponding ring-core few-mode erbium-doped fiber amplifier (RC-FM-EDFA). Meanwhile, in comparison with uniform core doping design, the saturation input signal power of the RC-FM-EDFA can be enhanced from -17.7 dBm and -16 dBm to -8.5 dBm for LP <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">01</sub> and LP <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sub> modes, respectively. Consequently, our proposed RC-FM-EDFA is characterized by both low differential modal gain (DMG) and the enhanced saturation input signal power. Those new characteristics of the RC-FM-EDFA is ideally desired for future agile networks.

SKKL PERFORMANCE ANALYSIS OF SUBMARINE CABLE COMMUNICATION SYSTEM (SKKL) EDFA - SOA AMPLIFIER LINK JAVA – BALI USING OPTISYSTEM

The Submarine Cable Communication System (SKKL) is a communication backbone that is deployed under the sea that used to connect networks between islands and between countries. DWDM (Dense Wavelength Division Multiplexing) technology can support long distance communication. Repeater used to reduce the impact of loss, on the detector side the signal can be detected properly. EDFA (Erbium Doped Fiber Amplifier) and Semiconductor Optical Amplifier (SOA) amplifiers can minimize the impact of loss and increasing the gain of each amplifier. The EDFA (Erbium Doped Fiber Amplifier) is an optical amplifier that can work at a wavelength of 1550 nm which provides amplification for the input signal that passes through it which is doped with the element erbium (Er). SOA amplifier is an optical amplifier that utilizes cavity or room cavity to strengthen light. By using branching unit configuration and repeaterless, repeatered, and parallel in-line amplifier configuration and optical system software 7.0 with system reliability parameters such as Q-factor, Bit Error Rate, Power Receiver, and Signal to Noise Ratio with power variations (0 dBm, 2 dBm, 4 dBm, 6 dBm, 8 dBm) at a frequency of 100 GHz for 10 channels. The best result on the Q-Factor parameter is 15,928, the BER parameter is 5.87 x 10-057, the receiver power parameter is -10,319 dBm, and the SNR is 42,713 dB. In this research the best value obtained in the Parallel in-line configuration. So as the best average is in the Repeatered EDFA configuration.

Highly Enhanced OER Performance by Er-Doped Fe-MOF Nanoarray at Large Current Densities.

Great expectations have been held for the electrochemical splitting of water for producing hydrogen as a significant carbon-neutral technology aimed at solving the global energy crisis and greenhouse gas issues. However, the oxygen evolution reaction (OER) process must be energetically catalyzed over a long period at high output, leading to challenges for efficient and stable processing of electrodes for practical purposes. Here, we first prepared Fe-MOF nanosheet arrays on nickel foam via rare-earth erbium doping (Er0.4 Fe-MOF/NF) and applied them as OER electrocatalysts. The Er0.4 Fe-MOF/NF exhibited wonderful OER performance and could yield a 100 mA cm−2 current density at an overpotential of 248 mV with outstanding long-term electrochemical durability for at least 100 h. At large current densities of 500 and 1000 mA cm−2, overpotentials of only 297 mV and 326 mV were achieved, respectively, revealing its potential in industrial applications. The enhancement was attributed to the synergistic effects of the Fe and Er sites, with Er playing a supporting role in the engineering of the electronic states of the Fe sites to endow them with enhanced OER activity. Such a strategy of engineering the OER activity of Fe-MOF via rare-earth ion doping paves a new avenue to design other MOF catalysts for industrial OER applications.

Probing strong coupling between a microwave cavity and a spin ensemble with Raman heterodyne spectroscopy

Rare-earth ions in solids are under active investigation for quantum microwave-optical signal converters. Here, light passed through an Er:YSO crystal sitting in a driven microwave resonator develops modulation due to three-wave mixing in the erbium dopants. Strong coupling between the microwave cavity and the spins causes modulation when the microwaves are resonant with the spin-cavity polaritons rather than the spins. This work extends the rare-earth microwave-optical conversion to both millikelvin temperatures and isotopically pure dopants.

Coherent Control in the Ground and Optically Excited States of an Ensemble of Erbium Dopants

Ensembles of erbium dopants can realize quantum memories and frequency converters that operate in the minimal-loss wavelength band of fiber optical communication. Their operation requires the initialization, coherent control, and readout of the electronic spin state. In this work, we use a split-ring microwave resonator to demonstrate such control in both the ground and optically excited state. The presented techniques can also be applied to other combinations of dopant and host and may facilitate the further development of quantum memory protocols and sensing schemes.

Optimum Lasing Cavity for Erbium Doped Zinc Tellurite Glass Rods Embedded with Ag Nanoparticles

A laser cavity was constructed for excitation of erbium doped zinc tellurite glass rods embedded with various concentration of Ag nanoparticles. Central to the system is a Xenon flashlamp for optical pumping, and mirrors to amplify the light waves. The amorphousity of the glass rod was studied by X-ray diffraction and the existence of silver nanoparticles inside the glass was confirmed by high resolution transmission electron microscopy analysis. The photoluminescence properties and differential thermal analysis curve of the samples confirmed the compatibility of the rods as gain medium. The rods were successfully fabricated and incorporated inside the laser cavity. The output of the laser with erbium doped zinc tellurite glass rods embedded with Ag nanoparticles was characterized via spectrum analyser and was found that the spectrum dominated at line 473 nm and 506 nm. The beam profiler was utilized to detect and display the laser beam in 3D.

Enhancing Performance of Coherent Optical OFDM FSO Communication Link Using Cascaded EDFA

Coherent communication aims to support high-speed dynamic networks by making their installation easier along with their monitoring and maintenance. In addition, Orthogonal Frequency Division Multiplexing (OFDM) which has shown gradual emergence in radio frequency (RF) domain during the past years, has now encroached into the optical domain. Combination of these two provides vigorous dispersion transmission as well as enhanced spectral efficiency. Free Space Optical (FSO) communication link performance deteriorates with scintillations, atmospheric turbulences and weather induced attenuations. The optical amplifiers, their arrangement used in the FSO link design has a drastic influence on the performance of the link. This work involves evaluating the proposed Coherent Optical OFDM FSO communication link at 30 Gbps data rate using Cascaded Erbium Doped Fiber Amplifier. The system has been evaluated in clear weather, rainfall and fog (Moderate to Dense) in terms of Q-Factor, BER, SNR and constellation diagram. The system has been designed considering moderate turbulent environment and geometric losses. The FSO communication link shows optimal performance up to 26 km for clear weather, 3.73 km under rainfall, 1.44 km under moderate foggy and 0.66 km under dense foggy environment.

Extinction Ratio and the Fiber Optic Transmission Networks

In the fiber optic communication network for example,- FTTH, EPON, NBN, OTN and so on, the most important components are fiber length between transmitter and receiver point. So, to make, cheap and meaningful communication through optical fiber it must be required to calculate how and what amount of signal is transmitted with the given length of the fiber. Finally, it is said that the optical fiber network have several limitations like extension ratio. So, it is necessary to investigate its affect on the performance of the Optical Network. This research is based on simulation by OptiSystem 0.17 on the basis of Dense wavelength division multiplex (DWDM) technology, Erbium Doped Fiber Amplifier (EDFA), dispersion Compensating Fiber (DCF) and single mode fiber of length 50–100 km.

EDFA AND EYCDFA POWER BOOSTER FOR SECURED, HIGH SPEED AND MULTIPLE WAVELENGTH SERVICES IN OPTICAL COMMUNICATION SYSTEMS USING WDM AND QUAD-SINGLE FORWARD AND TRI BACKWARD PUMPING TECHNIQUE

Proposed the EDFA and EYCDFA power booster (Erbium Doped Fiber Amplifier- Erbium ytterbium co doped fiber amplifier) with quad pumping for high speed and multi wavelength services in an optical communication. The proposed EDFA and EYCDFA power booster with WDM(Wavelength division multiplexing) simulated by dual forward and Backward pumping, Dual-backward pumping, Tri-single forward and dual backward pumping and Quadsingle forward and tri-backward pumping with respect to Pump power and fiber Length. The parameters Input Optical power, Output Optical power, Forward Signal power, Backward Signal power measured and determined the speed of transmission in all types of pumping methods. From that the proposed EDFA- ans EYCDFA power booster with WDM quad pumping is the best suitable for secured high speed optical telecommunication systems. The results shown in Quad pumping Output optical power is maximum 25.2dB and optimum spectral forward Signal power is 30.5dBm and very less spectral optical backward signal power of -25.4dBm with Length 5m