Showing papers on "Erbium published in 1994"
TL;DR: In this paper, a harmonically and regeneratively modelocked erbium fiber ring laser at 1.55 mu m for the first time was reported. But this was achieved with a high speed photodetector and a high Q dielectric filter.
Abstract: The authors report the operation of a harmonically and regeneratively modelocked erbium fibre ring laser at 1.55 mu m for the first time. Harmonic regenerative modelocking was achieved by feeding back the harmonic longitudinal beat signal which was detected with a high speed photodetector and a high Q dielectric filter. The repetition rate was 10 GHz and the soliton effect shortened-the pulse width from 7.0 to 2.7 ps.
249 citations
01 Aug 1994
TL;DR: In this article, the authors report the fabrication of silicon-rich erbium-doped silica films that exhibit both 1535 nm fluorescence and visible photoluminescence.
Abstract: We report the fabrication by PECVD of silicon-rich erbium-doped silica films that exhibit both 1535 nm fluorescence and visible photoluminescence. Fluorescence spectra are presented along with absorption spectra that display a strong band edge in the blue, which we ascribe to the presence of Si microclusters. We are unable to observe characteristic Er3+ absorption bands and propose that excitation of the rare earth is via an energy transfer process from Si microclusters.
206 citations
TL;DR: In this paper, the authors report the fabrication of silicon-rich erbium-doped silica films that exhibit both 1535 nm fluorescence and visible photoluminescence.
Abstract: We report the fabrication by PECVD of silicon-rich erbium-doped silica films that exhibit both 1535 nm fluorescence and visible photoluminescence. Fluorescence spectra are presented along with absorption spectra that display a strong band edge in the blue, which we ascribe to the presence of Si microclusters. We are unable to observe characteristic Er3+ absorption bands and propose that excitation of the rare earth is via an energy transfer process from Si microclusters.
199 citations
TL;DR: This work has demonstrated cw laser operation at wavelengths near 3 microm from monolithic, Er-doped YSGG, GGG, and YAG lasers by direct upper-state pumping in the 0.97-microm wavelength region with either a Ti:sapphire laser or InGaAs diode lasers.
Abstract: We have demonstrated cw laser operation at wavelengths near 3 μm from monolithic, Er-doped YSGG, GGG, and YAG lasers by direct upper-state pumping in the 0.97-μm wavelength region with either a Ti:sapphire laser or InGaAs diode lasers. We have obtained slope efficiencies as high as 31% and, with diode-laser pumping, output powers of 0.5 W. In addition, we have demonstrated tunable single-frequency operations from Er:YAG.
181 citations
Patent•
21 Oct 1994
TL;DR: In this article, the Kerr model-knocking was applied to an erbium fiber laser, where a chirped fiber Bragg grating was employed as the dispersive element.
Abstract: The invention relates to modelocked lasers including highly dispersive optical elements. The dispersive optical elements increase the oscillation pulse width inside the laser oscillators, which reduces the nonlinearity of the laser cavity for a given oscillating pulse energy. Compared to conventionally designed modelocked lasers, an increase in output pulse energy by one to three orders is achieved. As way of example, the technique is applied to an erbium fiber laser, where a chirped fiber Bragg grating is employed as the dispersive element. By using a Kerr-modelocking technique, a high nonlinearity may be sustained inside the fiber laser cavity, which leads to the generation of pulses with psec widths and energies up to 2 nJ. The large bandwidth of the chirped fiber Bragg grating allows a wavelength tuning range in excess of 10 nm, which is achieved by polarization control and a control of the gain spectrum of the laser.
122 citations
TL;DR: An environmentally stable Kerr-type mode-locked erbium fiber laser producing 360-fs near-bandwidth-limited pulses is demonstrated.
Abstract: We demonstrate an environmentally stable Kerr-type mode-locked erbium fiber laser producing 360-fs near-bandwidth-limited pulses. Environmentally stable operation is possible in the presence of nonpolarization-maintaining fiber components provided that their overall length is short compared with the length of the polarization-maintaining fiber components. The pulses are generated at a stable repetition rate of 27 MHz and have an energy content of 60 pJ.
120 citations
TL;DR: In this article, an erbium-doped silica-based planar waveguide amplifier integrated with a directional coupler which multiplexes the signal and pump light was achieved. But this was achieved with a low noise figure of 5.0 dB.
Abstract: A high gain of 27 dB is achieved in an erbium-doped silica-based planar waveguide amplifier integrated with a directional coupler which multiplexes the signal and pump light. A low noise figure of 5.0 dB is attained with the planar amplifier by using an integrated coupler which is formed of erbium-doped silica-based waveguides.
100 citations
TL;DR: In this article, the authors measured the polarization hole burning of an erbium doped fiber amplifier with a weak probe and showed that the maximum gain occurs for probe polarizations orthogonal to the signal.
Abstract: Measurement of polarization hole burning is reported for an erbium doped fiber amplifier. This effect produces a dependence of gain, measured with a weak probe, on the polarization of the saturating signal; the maximum gain occurs for probe polarizations orthogonal to the signal. The pump also contributes to the gain dependence on polarization. Reduction of the degree of polarization of both pump and signal below 10% reduces the polarization dependent gain substantially. >
95 citations
TL;DR: In this article, an erbium-doped fiber laser with an intracavity nonlinear absorptive wave mixing of the counter propagating beams was used to obtain linewidth of the order of a few kilohertz.
Abstract: Narrow-linewidth, single longitudinal mode operation is demonstrated in an erbium-doped fibre laser with an intracavity nonlinear absorptive wave mixing of the counter propagating beams. An unpumped length of erbium-doped fibre serves as the saturable absorber. Linewidths of the order of a few kilohertz are obtained.
87 citations
TL;DR: In this article, a 15 dB, gain controlled, 1480 nm pumped, erbium doped silica fiber amplifier is demonstrated with < 0.2 dB of gain variation for signal input levels up to −5 dBm.
Abstract: A 15 dB, gain controlled, 1480 nm pumped, erbium doped silica fibre amplifier is demonstrated with < 0.2 dB of gain variation for signal input levels up to –5 dBm. Gain control is effected by concomitant lasing at 1520 nm using Bragg grating reflectors. No error rate penalty is observed for a signal modulated at 2.5 Gbit/s.
87 citations
Patent•
AT&T1
TL;DR: In this article, the stability of a pump laser for activating an erbium amplifier is enhanced by a grating which results in laser operation in the coherence collapse regime, and the grating can be used to improve the performance of the pump laser.
Abstract: Stability of a pump laser for activating an erbium amplifier is enhanced by a grating which results in laser operation in the coherence collapse regime.
TL;DR: In this article, a 170 fs transform-limited pulse train at 10 GHz has been successfully generated for the first time with a picosecond stable fibre laser and a dispersiondecreasing erbium-doped fiber amplifier.
Abstract: A 170 fs transform-limited pulse train at 10 GHz has been successfully generated for the first time with a picosecond stable fibre laser and a dispersion-decreasing erbium-doped fibre amplifier which acts as a very efficient active soliton pulse compressor.
TL;DR: In this article, a numerical analysis of planar and channel silica waveguide amplifiers with high erbium concentration is presented, based on the combined use of a full-vectorial finite-element method and the Runge-Kutta algorithm.
Abstract: We report numerical analysis of planar and channel silica waveguide amplifiers with high erbium concentration. The numerical approach is based on the combined use of a full-vectorial finite-element method and the Runge-Kutta algorithm. It allows one to investigate real structures, accounting for both the active ions interactions by cross-relaxation and upconversion and the effects of waveguide geometry and refractive index profile. We show that, depending on input pump power and waveguide structure, ion-ion interactions affect the amplifier performance for high erbium concentrations. A three-dimensional waveguide designed for single-mode operation ensures higher pumping efficiency and lower noise characteristics than a two-dimensional one and seems to be the best candidate to overcome this drawback. >
TL;DR: In this article, the transient response of an erbium-doped fiber amplifier (EDFA) pumped at 1.48 /spl mu/m, taking into account the gain-saturation effects due to the amplified spontaneous emission (ASE), is studied theoretically and experimentally.
Abstract: The transient response of an erbium-doped fiber amplifier (EDFA) pumped at 1.48 /spl mu/m, taking into account the gain-saturation effects due to the amplified spontaneous emission (ASE), is studied theoretically and experimentally. The theoretical model is used to predict the gain saturation and recovery times of an EDFA and its effects to the amplification of optical pulses. >
TL;DR: In this article, a modelocked, polarisation-maintaining Er-doped fiber ring laser with a single-polarisation fiber amplifier and an uncompensated polarisation bias section are integrated into the laser.
Abstract: Subpicosecond pulses have been generated in an actively modelocked, polarisation-maintaining Er-doped fibre ring laser. A single-polarisation fibre amplifier and an uncompensated polarisation bias section are integrated into the laser. This laser combines the nonlinear pulse-shortening mechanism of polarisation-rotation lasers and the single-polarisation operation, environmental insensitivity, and capacity for active modelocking characteristic of unidirectional single-polarisation ring lasers.
TL;DR: In this paper, the first q-switched operation of a 2.7 µm fluorozirconate fiber laser was shown, where an acousto-optic modulator and a rotating mirror were used as switching elements.
Abstract: Q-switched operation of a 2.7 µm fluorozirconate fibre laser is shown for the first time. An acousto-optic modulator and a rotating mirror were used as switching elements. Pulse durations of 100 ns and peak powers exceeding 2 W were achieved.
TL;DR: In this article, a dual-wavelength operation of a diode-pumped, passively mode-locked, ytterbium-erbium "figure-of-eight" (F8L) fiber laser has been achieved by including tunable filters and/or fiber gratings in the laser cavity.
TL;DR: In this article, the growth conditions of gallium arsenide doped with erbium have been studied and shown to lead to bifurcated structures, referred to as quantum trees.
Abstract: Gallium arsenide doped with erbium has been grown by molecular beam epitaxy. At growth temperatures in the range 540–605 °C, and with arsenic to gallium flux ratios of 2 and more, the erbium forms uniform crystalline microprecipitates of ErAs when the concentration exceeds 7×1017 cm−3. The diameter can be varied in the range 11–21 A by altering the growth temperature. Reducing the arsenic to gallium flux ratio to close to stoichiometry changes the growth mode to one yielding quantum wires aligned in the growth direction. Subtle changes in growth conditions lead to bifurcated structures, which we refer to as quantum trees.
TL;DR: Saturable absorber Q switching of the Er:glass laser at 1533 nm using U4+:SrF2 has been obtained using a 2.69mm-thick Q switch in a 14 cm−long plane-parallel cavity, with a 3×50 mm Kigre QE•7S er:glass rod as discussed by the authors.
Abstract: Saturable absorber Q switching of the Er:glass laser at 1533 nm using U4+:SrF2 has been obtained. Q‐switched pulses of 3 mJ and 60 ns full width at half‐maximum were achieved using a 2.69‐mm‐thick Q switch in a 14‐cm‐long plane‐parallel cavity, with a 3×50 mm Kigre QE‐7S Er:glass rod. The high absorption cross section of U4+:SrF2 resulted in efficient Q‐switched operation (without intracavity focusing) in agreement with the theoretical predictions.
TL;DR: In this article, the authors demonstrate self-starting soliton generation by inserting a travelling wave acousto-optic modulator and a bandpass filter in a diode-pumped erbium doped fiber ring laser.
Abstract: The authors demonstrate self-starting soliton generation by inserting a travelling wave acousto-optic modulator and a bandpass filter in a diode-pumped erbium doped fibre ring laser. The continuous frequency sliding of the circulating light inhibits CW oscillation, and favours the emission of solitons that are stably trapped by the filter.
TL;DR: In this paper, the spectral properties of thin film (Ho)−yttrium aluminum garnet (YAG) and Er•YAG emitters with a platinum substrate were investigated.
Abstract: Thin film (Ho)‐yttrium aluminum garnet (YAG) and Er‐YAG emitters with a platinum substrate exhibit high spectral emittance in the emission band (eλ≊0.75, 4I15/2–4I13/2, for Er‐YAG and eλ≊0.65, 5I7–5I8 for Ho‐YAG) at 1500 K. In addition, low out‐of‐band spectral emittance, eλ<0.2, suggest these materials would be excellent candidates for high efficiency selective emitters in thermophotovoltaic (TPV) systems operating at moderate temperatures (1200–1500 K). Spectral emittance measurements of the thin films were made (1.2<λ<3.0 μm) and compared to the theoretical emittances calculated using measured values of the spectral extinction coefficient.
TL;DR: In this paper, a passively mode-locked erbium-doped fiber laser source provides the seed pulses for a femtosecond (F2F) amplifier with a repetition rate of 33 MHz with an energy content as high as 1.4 nJ.
TL;DR: What is believed to be the shortest Er:Yb phosphate-glass fiber Fabry-Perot laser ever reported is demonstrated, having a 100-microm cavity length and a continuous wavelength tuning range over 4.52 nm (limited by the sharp fiber gain peak).
Abstract: A compact tunable single-mode fiber laser is developed by using a novel combination of high-gain erbium: ytterbium (Er:Yb) phosphate fiber and fiber Fabry-Perot (FFP) cavity configurations. Experiments demonstrate the shortest Er:Yb phosphate FFP laser ever reported, which has a 100µm cavity length with a continuous wavelength tuning range over 4.52nm, as limited by the sharp fiber gain peak. In addition, an alternative 3-mirror laser design has also demonstrated single-mode lasing operation.
27 Jul 1994
TL;DR: In this paper, a new erbium doped phosphate laser glass has been developed, which exhibits improved thermal shock resistance and superior laser performance, and it has been tested on spectral, spectral and thermo-mechanical properties.
Abstract: New erbium doped glass base compositions and sensitizer ion concentrations have been investigated. Laser, spectral, and thermo-mechanical properties have been tested. This study has resulted in a new erbium doped phosphate laser glass that exhibits improved thermal shock resistance and superior laser performance.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
TL;DR: A unidirectional erbium fiber laser incorporating a novel LiNbO(3) overlay fiber-optic bandpass filter is demonstrated and can be tuned from 1531 to 1556 nm while maintaining a bandwidth of less than 0.2 nm (resolution limited).
Abstract: A unidirectional erbium fiber laser incorporating a novel LiNbO(3) overlay fiber-optic bandpass filter is demonstrated. By applying index-matching oils of different refractive indices to the surface of the overlay filter, we could tune the operating wavelength of the laser from 1531 to 1556 nm while maintaining a bandwidth of less than 0.2 nm (resolution limited). Output powers as high as 3 mW for 36 mW of pump power have been recorded.
TL;DR: In this article, the concept of a tunable erbium-doped fiber ring laser based on a reflection Mach-Zehnder interferometer was presented, which gave a tuning range of 39 nm.
Abstract: The concept of a tunable erbium-doped fiber ring laser based on a reflection Mach-Zehnder interferometer is presented. The principle of operation is demonstrated with a fiber version of the interferometer which gave a tuning range of 39 nm. With current electro-optic devices, high speed tuning should be possible. >
Patent•
26 Oct 1994TL;DR: In this paper, a new infrared-to-visible up-conversion material is provided which can be applied to an infrared light identification element having a useful conversion efficiency and sensitivity for infrared light in the wavelength of 1.5 μm, 0.98 μm and 0.8 μm bands.
Abstract: A new infrared-to-visible up-conversion material is provided which can be applied to an infrared light identification element having a useful conversion efficiency and sensitivity for infrared light in the wavelength of 1.5 μm band, 0.98 μm band and 0.8 μm band without the necessity of previous excitation of the material. This infrared-to-visible up-conversion material consists of an inorganic material comprising at least two elements of erbium (Er) and a halogen or compounds thereof.
TL;DR: In this article, a single erbium doped fiber amplifier was measured and the magnitude of the effect of the operating conditions of the amplifier was characterized as a function of the polarisation dependent gain.
Abstract: Polarisation dependent gain is measured in a single erbium doped fibre amplifier. The magnitude of the effect is characterised as a function of the operating conditions of the amplifier.
Patent•
IBM1
TL;DR: In this paper, a CVD process for producing rare earth-doped, epitaxial semiconductor layer on a substrate is disclosed. Butler et al. used a silane or germane and a rare earth compound in the gas phase.
Abstract: A CVD process for producing a rare earth-doped, epitaxial semiconductor layer on a substrate is disclosed. The process utilizes a silane or germane and a rare earth compound in the gas phase. By this method single phase, rare earth-doped semiconductor layers, supersaturated in the rare earth, are produced. The preferred rare earth is erbium and the preferred precursors for depositing erbium by CVD are erbium hexafluoroacetylacetonate, acetylacetonate, tetramethylheptanedionate and flurooctanedionate. The process may be used to produce optoelectronic devices comprising a silicon substrate and an erbium-doped epitaxial silicon film.
Patent•
AT&T1
TL;DR: In this paper, a 980 nm pump, for use with an erbium-doped fiber amplifier, provides redundancy together with simultaneous pumping, both copropagating and counter-propagation, relative to 1550 nm signal, without need for an isolator.
Abstract: A 980 nm pump, for use with an erbium-doped fiber amplifier, provides redundancy together with simultaneous pumping, both co-propagating and counter-propagating, relative to 1550 nm signal, without need for an isolator.