Showing papers on "Erbium published in 1999"
TL;DR: In this article, a comprehensive review of the work done by our group on diode-pumped bulk erbium-ytterbium microlasers is presented, starting from an analysis of the optical properties of Er-Yb doped phosphate glasses, addressed to the modeling of the active material and to the design and optimization of laser cavities, different operating regimes and peculiar properties of these novel laser devices are described and discussed.
155 citations
TL;DR: Samples of erbium (III) tris(8-hydroxyquinoline) (ErQ) have been prepared and their photoluminescence measured as mentioned in this paper, and clearly resolved peaks due to intra-atomic transitions between the 4I13/2 and 4I15/2 levels can be observed at room temperature.
Abstract: Samples of erbium (III) tris(8-hydroxyquinoline) (ErQ) have been prepared and their photoluminescence measured. Clearly resolved peaks due to intra-atomic transitions between the 4I13/2 and 4I15/2 levels can be observed at room temperature. The possibility of depositing ErQ on to silicon to produce organic electroluminescent diodes offers the possibility of a cheap 1.5 μm emitter based on silicon technology.
131 citations
TL;DR: In this article, the first 3-mm fiber laser of the 1-W class was demonstrated with a double-clad erbium-doped ZBLAN fiber diode pumped at 790 nm, achieving 1.7 W of output power and 17.3% slope efficiency with respect to the launched pump power.
Abstract: We report what is to our knowledge the first 3-mm fiber laser of the 1-W class. 1.7 W of output power and 17.3% slope eff iciency (with respect to the launched pump power) at a wavelength of 2.71 mm are demonstrated from a double-clad erbium-doped ZBLAN fiber diode pumped at 790 nm. Energy transfer from the Er3+ lower laser level to a Pr3+ codopant decreases ground-state bleaching and excited-state absorption, thus avoiding output-power saturation. This result represents more than an order-of-magnitude improvement over previous work of which we are aware. Advantages over current crystal-laser designs include nearly transverse fundamental-mode operation, reduced thermal effects, and ease of use, e.g., in medical endoscopy.
128 citations
TL;DR: In this paper, the phase separation process was investigated using thermal and structural analysis, and changes were observed in the optical properties of the glass after reheating (10 h at 360°C).
Abstract: Erbium doped oxy-fluoride glass-ceramics (50GeO2,[50−x]PbO,xPbF2) have been prepared by thermal treatments of as-melted glass. The optical absorption and emission cross-sections were measured. The controlled crystallisation of the fluoride compounds by nucleation and growth in the oxide matrix produced crystallites ∼10 nm in size and a filling factor of 10−2. The phase separation process was investigated using thermal and structural analysis. Changes were observed in the optical properties of the glass after reheating (10 h at 360°C). The inhomogeneous linewidth of the 4I15/2↔4S3/2 transition was reduced by 50% by incorporating most of the Er ions in the crystalline phase. An increase of the maximum absorption cross-section, up to 100%, was obtained at room temperature.
113 citations
TL;DR: In this paper, a spectral emittance model for films of rare earth containing materials was developed and good agreement between experimental and theoretical spectral emittances was found for erbium, thulium and erbiam-holmium aluminum garnets.
Abstract: As a result of their electron structure, rare earth ions in crystals at high temperature emit radiation in several narrow bands rather than in a continuous blackbody manner. This study develops a spectral emittance model for films of rare earth containing materials. Although there are several possible rare earth doped high temperature materials, this study was confined to rare earth aluminum garnets. Good agreement between experimental and theoretical spectral emittances was found for erbium, thulium and erbium-holmium aluminum garnets. Spectral emittances of these films are sensitive to temperature differences across the film. Emitter efficiency is also a sensitive function of temperature. For thulium aluminum garnet the efficiency is 0.38 at 1700 K but only 0.19 at 1262 K.
88 citations
TL;DR: In this article, the preparation of discrete erbium-doped silicon nanoparticles by co-pyrolysis of disilane and the volatile complex Er(tmhd)3 (tmhd = 2,2,6,6-tetramethyl-3,5-heptanedionato) is described.
Abstract: The preparation of discrete erbium-doped silicon nanoparticles prepared by the co-pyrolysis of disilane and the volatile complex Er(tmhd)3 (tmhd = 2,2,6,6-tetramethyl-3,5-heptanedionato) is described. The nanoparticles were characterized by transmission electron microscopy, selected area electron diffraction, X-ray dispersive spectroscopy, photoluminescence, and UV−visible absorption spectroscopies. Erbium-doped silicon nanoparticles possess a distinctive dark contrast in the transmission electron microscope, and the presence of erbium is confirmed by X-ray energy dispersive spectroscopy. The mean diameter of the nanoparticle aggregates can be shifted by altering the length of the pyrolysis oven employed. Chacteristic Er3+ near-infrared photoluminescence at 1540 nm is detected in these doped nanoparticles; preliminary excitation and power dependence measurements of this luminescence suggest a carrier-mediated emission mechanism.
78 citations
TL;DR: Clinical use of erbium laser for stapedotomy is discontinued until the problem of temporary acoustic traumatization is resolved, after observing an immediate postoperative middle and high frequency loss of up to 75 dB on bone conduction threshold measurements 2 h after surgery, suggesting anoustic traumatization by the erBium laser.
Abstract: Among different types of lasers, the erbium laser exhibits particularly favourable characteristics for ear surgery. Experiments with application of erbium laser pulses to the isolated stapes connec...
60 citations
TL;DR: In this article, a passive Q-switched erbium-doped fiber laser can be constructed by inserting a segment of samariumdoped fibre into the ring cavity as saturable absorber.
59 citations
TL;DR: In this article, an energy transfer by a Forster mechanism, based on resonant dipole coupling, was proposed, which quenches efficiently the luminescence of the host in the case of large erbium concentration.
Abstract: The simultaneous study of absorption, luminescence, and ODMR spectra of erbium doped a-Si:H and a SiCx:H alloy reveals that Er3+ ions are pumped by a resonant but nonradiative energy transfer from electron–hole pairs excited in the host. Direct optical pumping into absorption lines of Er3+ is not observed. The emission of the Er3+ ions is strong and decreases only moderately from 77 K to room temperature. We propose an energy transfer by a Forster mechanism, based on resonant dipole coupling, which quenches efficiently the luminescence of the host in the case of large erbium concentration. Resonance of electron–hole pairs to the excited state of the rare earth ion is achieved as electrons thermalize in tail states.
56 citations
TL;DR: In this article, LiNbO 3 co-doped with Er 3+ and Yb 3+ has been grown by the Czochralski technique, from melts having a fixed erbium concentration (0.5 ǫ ) and different ytterbium concentrations ( 0.1, 0.5, 1.0, 1.5 and 2.0 ) using optical absorption measurements, which indicate the efficient incorporation of the rare-earth ions to the crystal, with the absorption bands characteristic of the 3 + valence.
53 citations
TL;DR: In this article, it was shown that the band shape of the 4I13/2 → 4I15/2 transition depends on the annealing temperature, and that the tetragonal phase mainly appears at 800°C, although both monoclinic and tetragonic phases are simultaneously detected in undoped waveguides at this temperature.
Patent•
04 Oct 1999
TL;DR: In this article, an ultra-wide bandwidth optical amplifier for the 1.5 μm optical band was proposed, which divides the 1520 nm-1610 nm bandwidth into three narrow bandwidths, and uses three separate erbium doped fiber amplifier blocks, configured in parallel relation and individually optimized to separately amplify the respective bandwidth.
Abstract: An ultra-wide bandwidth optical amplifier for the 1.5 μm optical band divides the 1520 nm-1610 nm bandwidth into three narrow bandwidths, i.e. C 1 (1520 nm-1541 nm), C 2 (1541 nm-1565 nm) and L (1565 nm-1610 nm), and uses three separate erbium doped fiber amplifier blocks, configured in parallel relation and individually optimized to separately amplify the respective bandwidth. Multipath interference is controlled by constructing all three amplifier blocks with the same optical transmission length. The C 1 and C 2 band amplifier blocks, which include shorter erbium doped fibers than the L band amplifier block, are physically lengthened using lengths of single mode fiber so that the total length of the optical transmission path of each amplifier block is generally equal. Fiber lengths are controlled to within 500 microns. Selected amplifier blocks further include delay control devices which selectively delay signals passing through the respective amplifier block to provide fine adjustment to signal recombination.
TL;DR: The laser performance of bulk samples with various ErF(3) contents was investigated with respect to the optimum doping concentration, which is estimated to be higher than 8 mol.
Abstract: We report on the laser emission of erbium-doped fluoride glasses in the spectral range from 2.7 to 2.8 mum . The pump source was a fiber-coupled InGaAs semiconductor laser emitting near lambda(p)~970 nm . The laser performance of bulk samples with various ErF(3) contents was investigated with respect to the optimum doping concentration, which is estimated to be higher than 8 mol. %. A maximum output power of P(out) > 160 mW and a slope efficiency of eta = 10% were achieved. Results are compared with previously published data on erbium-doped ZBLAN fiber and LiYF(4) crystal lasers.
TL;DR: In this paper, the authors demonstrate stable, self-starting, passive Q-switching of both erbium and ytterbium fiber laser cavities operating at wavelengths of 1550 and 1030 nm, respectively.
Abstract: Using a nonlinear cavity element, a liquefying gallium mirror, we demonstrate stable, self-starting, passive Q-switching of both erbium and ytterbium fiber laser cavities operating at wavelengths of 1550 and 1030 nm, respectively. The performance at 1550 nm is shown to be equivalent to that achieved with a state of the art semiconductor saturable absorber designed to work at this wavelength. The results highlight the suitability of this tremendously broadband, inexpensive nonlinear medium for a wide range of passive Q-switch applications.
TL;DR: In this paper, the absorption and luminescence properties of Er3+ ions doped into single crystals of the tetragonal-symmetry host LuPO4 are reported, and the fluorescence decay of the 4 I 13/2 − 4 I 15/2 emission was found to be governed by a single exponential decay process when excited with a low-intensity pump source.
TL;DR: An erbium fiber laser is described that is passively mode locked by a novel, precision antireflection-coated semiconductor saturable-absorber mirror that incorporates an additional two-photon absorber.
Abstract: We describe an erbium fiber laser that is passively mode locked by a novel, precision antireflection-coated semiconductor saturable-absorber mirror that incorporates an additional two-photon absorber. It is shown that passive mode locking evolves from a Q?switching instability. The results are achieved by use of saturable absorbers that provide a large (15%) nonlinear (saturable) loss. Exploiting two-photon absorption can substantially reduce the peak power of the Q?switched pulses, which results in improved reliability of the laser. Moreover, two-photon absorption can be used to produce an optimal stability range for saturable-absorber mode locking.
TL;DR: In this article, the local structure of erbium-doped silicon produced by the laser ablation technique is investigated by Er LIII-edge x-ray absorption fine structure analysis.
Abstract: The local structure of erbium-doped silicon produced by the laser ablation technique is investigated by Er LIII-edge x-ray absorption fine structure analysis. The combined analysis of extended x-ray absorption fine structure analysis and an x-ray absorption near-edge structure simulation based on multiple-scattering theory reveals the most probable atomic coordination of the optically active center; Er bonded with six oxygen atoms has a C4v symmetry. The optical activation process of this system is also discussed. The Si target with 10 wt% Er2O3 has two kinds of local structures, C-rare-earth Er2O3 grain and another Er phase incorporated in Si. The laser ablation homogenizes these phases, and deposits a new single-phase structure of the octahedron (Oh point group) on the substrates. In this phase, the optical transition probability is low due to the forbidden 4f transition of Er in the crystal field originating from the higher-order symmetry of O. After annealing, degradation of the symmetry from Oh to C4...
TL;DR: In this paper, a green room temperature up-conversion laser has been demonstrated in a 120 µm diameter microsphere of Er3+ doped ZBLAN, where the lasing occurs around 540 nm with a 801 nm diode laser pump.
Abstract: A green room temperature up-conversion laser has been demonstrated in a 120 µm diameter microsphere of Er3+ doped ZBLAN. Lasing occurs around 540 nm with a 801 nm diode laser pump. The lasing threshold of only 30 µW of absorbed power is over two orders of magnitude lower than the lowest previously observed.
TL;DR: In this article, a wavelength-tunable actively mode-locked erbium fiber ring laser was demonstrated using a Fabry-Perot semiconductor modulator, which played the simultaneous roles of an intensity mode locker and a tunable optical filter.
Abstract: A wavelength-tunable actively mode-locked erbium fiber ring laser was demonstrated using a Fabry–Perot semiconductor modulator. The modulator played the simultaneous roles of an intensity mode locker and a tunable optical filter. Stable single- or dual-wavelength nearly transform-limited picosecond pulses at gigabit repetition rates were generated. Continuous wavelength tuning was achieved by simply controlling the temperature of the modulator. Pulse train with a repetition rate up to 19.93 GHz (eight times the driving frequency) was obtained by using rational harmonic mode-locking technique.
TL;DR: In this paper, a numerical model for spiral and folded erbium-doped planar waveguide amplifiers was developed, based on a rate equation model of the local complex dielectric constant and beam propagation by the method of lines.
Abstract: A numerical model for spiral and folded erbium-doped planar waveguide amplifiers has been developed, based on a rate equation model of the local complex dielectric constant and beam propagation by the method of lines. A five-level system is used to describe the ion-ion interactions that occur at high erbium concentrations. A suitable form of the method of lines is presented in polar coordinates, and absorbing boundary conditions based on the third-order rational series approximation are derived. Using this model, amplification in both straight and curved slab guides can be simulated, and examples of propagation in typical folded amplifier structures are presented.
TL;DR: In this paper, the spontaneous emission control of rare earth ions implanted inside planar multidielectric microcavities is investigated theoretically and experimentally, and it is shown that a large amount of the emitted power is carried by the guided modes of the structures.
TL;DR: Singlemode high erbium-doped phosphate glass fibres have been designed and fabricated in this article, achieving a net gain of 2.1 dB/cm at 1537 nm with a pump diode power of 110 mW at 980 nm.
Abstract: Singlemode high erbium-doped phosphate glass fibres have been designed and fabricated. Gain measurements in a 2.15 cm fibre with an Er/sup 3+/ concentration of 3.7/spl times/10/sup 20/ rm/sup -3/ were performed. A net gain of 2.1 dB/cm at 1537 nm was demonstrated with a pump diode power of 110 mW at 980 nm.
TL;DR: In this paper, the 1.54 μm Er3+ photoluminescent properties of erbium-doped Si/SiO2 superlattices are investigated.
Abstract: The 1.54 μm Er3+ photoluminescent properties of erbium-doped Si/SiO2 superlattices are investigated. Two superlattice films, one with erbium in Si layers and the other with erbium in SiO2 layers, were prepared by electron cyclotron resonance plasma-enhanced chemical vapor deposition of SiH4 and O2 with cosputtering of erbium and subsequent rapid thermal anneal. Both display Er3+ luminescence, but it is stronger with longer luminescent lifetime and less temperature quenching when erbium is in the SiO2 layer. The results demonstrate that by using quantum structures, nonradiative deexcitation of Er3+ may be suppressed, and that carrier recombination events, which excite Er3+ ions, may be physically separated from Er atoms and still lead to an efficient Er3+ luminescence.
Patent•
09 Mar 1999
TL;DR: A fiber laser with square inner cladding has a single core codoped either with Ytterbium or Erbium, or with Thulium and Holmium at a ratio of at least 10:1 operating in a single mode to provide eye-safe radiation with wavelengths above 1.5 micron.
Abstract: A fiber laser 10 with square inner cladding 12, 29 may have a single core 11 codoped either with Ytterbium or Erbium or with Thulium and Holmium at a ratio of at least 10:1 operating in a single mode to provide eye-safe radiation with wavelengths above 1.5 micron. The single core laser has a pump clad cross sectional area about 2(10) 3 greater than the cross sectional area of the core. A multi-core laser has a plurality of single mode cores 28 doped with any rare earth ions, the cores equally spaced by at least two core diameters in an isometric array, in a cavity having a finesse of greater than ten, to produce a single, very bright phase-locked beam in the fundamental supermode. A method starts with hexagonal cladded-core rods 35, 36 in an isometric array, which are then fused and drawn down.
01 Apr 1999
TL;DR: In this article, the effect of different glass types on the properties of rare earth ions is considered in detail on the absorption and emission transitions of Nd3+ and Er3+ in the infrared region.
Abstract: Rare earth ions are widely used in lasers and amplifiers. Depending on the device, there are different demands on the properties of the active ions and on the host glass. Thus, an extensive characterization and comparison of both host matrix properties and spectroscopic properties of rare earth ions for various glass types is of special interest. In this study, fluoride and phosphate based glasses on the one side and heavy metal oxide containing glasses such as Bi-borate, Pb-Bi-gallate and K-tantalate-gallate glasses on the other side were investigated in order to figure out the advantages of these different glass systems. UV-VIS and IR cut-off, phonon energy and refractive index were studied as characterization of the host matrix. Judd-Ofelt parameters, spontaneous emission probabilities and stimulated emission cross sections were calculated for Nd3+ and Er3+ ions. Peak wavelength, shape and linewidth of Nd3+ and Er3+ bands were determined from absorption and emission spectra. The effect of the different glass types on the properties of rare earth ions is considered in detail on the absorption and emission transitions of Nd3+ and Er3+ in the infrared region.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
TL;DR: In this paper, the impact of pump wavelength and input signal power on the output signal and backward spontaneous emission noise power of L-band erbium-doped fiber amplifiers is examined.
Abstract: The impact of pump wavelength and input signal power on the output signal and backward spontaneous emission noise power of L-band erbium-doped fiber amplifiers is examined. It is shown experimentally that tuning the pump wavelength /spl plusmn/30-nm away from the 980-nm absorption peak provides 3-5-dB improvement in pump-to-signal conversion.
TL;DR: In this paper, the authors presented the preparation and optical studies of waveguides in LiNbO 3 :Er/Yb formed by Zn-diffusion, and found that both impurities incorporated to the crystal, with a segregation coefficient of K eff = 1.5.
TL;DR: In this article, stable room-temperature electroluminescence (EL) at 1.54 μm from erbium-doped porous silicon devices under both forward and reverse bias conditions was demonstrated.
Abstract: We demonstrate stable room-temperature electroluminescence (EL) at 1.54 μm from erbium-doped porous silicon devices under both forward- and reverse-bias conditions. Erbium was infiltrated in the pores (⩽1019 cm−3) by cathodic electrochemical migration of the ions followed by high-temperature annealing (950–1100 °C) in an oxygen and nitrogen environment. The devices exhibit an exponential EL dependence in both bias conditions as a function of input power. In reverse bias, the external quantum efficiency reaches 0.01%. The EL intensity decreases by a factor of 24 for reverse bias and 2.6 for forward bias when the temperature increases from 240 to 300 K. The different device characteristics in forward and reverse biases suggest that different excitation mechanisms are responsible for EL.
TL;DR: In this paper, the authors explore fundamental aspects of BEFLs configured to generate multiple wavelengths with particular focus on the effects of the Brillouin and EDF pumps on the number of lines and the relationship between the intensities of individual lines in the comb.
Abstract: Laser sources with unique properties can be produced using a combination of nonlinear Brillouin gain in single-mode optical fibre (SMOF) and gain in erbium-doped fibre (EDF). Narrow bandwidth nonlinear gain from stimulated Brillouin scattering in SMOF determines the wavelength of operation, and gain in EDF allows efficient operation and large power extraction. Various cascading schemes based on the Brillouin/erbium fibre laser (BEFL) as well as distinctive multi-wavelength versions of the BEFL were proposed, being able to produce 10GHz combs of over 30 lines at 1550 nm. These multi-wavelength sources may be of use in future dense wavelength-division multiplexing systems. We explore fundamental aspects of BEFLs configured to generate multiple wavelengths with particular focus on the effects of the Brillouin and EDF pumps on the number of lines and the relationship between the intensities of the individual lines in the comb.
TL;DR: In this article, the results of a two-color spectroscopy in the visible and the mid-infrared on erbium-doped silicon (Si:Er) are presented.
Abstract: Results of a two-color spectroscopy in the visible and the mid-infrared on erbium-doped silicon (Si:Er) are presented. In the experiments, pulsed beam provided by a free-electron laser is directed on a sample under primary above-band-gap excitation with another laser. It is shown that the powerful infrared beam can be ionize carriers localized at shallow traps. Liberation of these carriers makes them available for excitation of erbium and thereby enhances the luminescence intensity. Identification of shallow levels responsible for the effect is discussed.