Search results for "erbium"
showing 10 items of 253 documents
Q-switching of an erbium-doped fibre laser modulated by a Bragg grating fixed to a piezoelectric
2003
The performance of the Q-switched erbium-doped fibre laser with two fibre Bragg gratings as cavity mirrors was theoretically analysed, employing a set of rate equations for the ion populations and the photon flux inside the cavity. The simulation considers a system where the pulsed laser emission is produced by the temporal modulation of a Bragg grating fixed to a piezoelectric and operating in the 1550 nm spectral region. The temporal evolution of different frequency components of the laser emission produced is governed by the instantaneous overlap between the two gratings. Theoretical results are in agreement with previously reported experimental values.
Synthesis of cubic and hexagonal NaYF4:Er3+
2012
Up-conversion luminescence process, which is related to absorption of several light photons (usually infrared) followed by emission of light in the visible or even ultraviolet spectral regions, has attracted interest of scientists due to its potential practical use in various applications including biolabels, temperature sensors, light sources etc. Although observable in d- and f-ions doped materials, the highest efficiency of up-conversion luminescence is usually attained in lanthanides doped hosts. Among huge variety of materials suitable as up-conversion hosts the most prominent is considered to be NaYF4, both due to its low phonon energy and multisite nature of the crystalline lattice. …
1.65-μm Er:Yb:YAG diode-pumped laser delivering 80-mJ pulse energy
2005
We demonstrate efficient lasing of bulk diode-pumped Er 31 :Yb 31 :YAG at 1.645 mm. The material is transversely pumped using three quasi-cw 960-nm laser diode arrays in a simple arrangement. In the free-running mode of operation, an output pulse energy of 79 mJ is obtained at 4.7 J of incident optical pump energy. The lasing threshold lies in the range 1.0 to 1.9 J in long-pulse operation, depending on pumping conditions, and optical slope efficiencies of 2.2% to 3.4% were measured with respect to the incident pump energy. Furthermore, initial Q-switching experiments with a Co:MALO saturable absorber yielded pulses of 1.7-mJ energy and 340-ns FWHM duration. As the reported laser setup also…
Atomic force microscopy visualization of injuries in Enterococcus faecalis surface caused by Er,Cr:YSGG and diode lasers
2014
Aim: To visualize by Atomic Force Microscopy the alterations induced on Enterococcus. faecalis surface after treatment with 2 types of laser: Erbium chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser and Diode laser. Material and Methods: Bacterial suspensions from overnight cultures of E. faecalis were irradiated during 30 seconds with the laser-lights at 1 W and 2 W of power, leaving one untreated sample as control. Surface alterations on treated E. faecalis were visualized by Atomic Force Microscopy (AFM) and its surface roughness determined. Results: AFM imaging showed that at high potency of laser both cell morphology and surface roughness resulted altered, and that several ce…
Characterization of optogeometric parameters of optical fibers by near-field scanning probe microscopies
2000
The combination of atomic-force and scanning-near-field optical microscopies is useful for characterizing the physical and optical parameters of optoelectronic devices. With a commercial atomic-force microscope adapted to perform scanning-near-field optical measurements, we succeed in determining core diameters, localizing the erbium doping zone, and analyzing propagation modes in erbium-doped and multimodal optical fibers.
Theoretical study of cascade laser in erbium-doped chalcogenide glass fibers
2010
International audience; A theoretical investigation of an innovative cascade laser source is performed. The main goal of the work is the design of a continuous-wave (CW) photonic crystal fiber (PCF) laser, based on an erbium-doped chalcogenide glass. Due to the comparable lifetimes of the 4I13/2, 4I11/2 and 4I9/2 erbium energy levels, the simultaneous emissions at the wavelengths close to 2.7 μm and 4.5 μm are obtained with a pump wavelength close to 806 nm (direct pumping into the level 4I9/2). This scheme could be useful to develop high efficiency, high beam-quality and compact Near-IR and Mid-IR oscillators with single-mode output for applications not only in surgery but also in spectros…
Generation of supercontinuum in erbium-doped microstructured optical fibers
2009
We present experimental results on supercontinuum (SC) generation in Er-doped microstructured optical fibers (MOF) pumped with nanosecond pulses at 1064 nm. The Er doping increases the effective nonlinear refractive index [1]. As a result, nonlinear interactions are enhanced and broad supercontinuum spectra are generated with relatively low pump power. Supercontinuum spectra generated in two fibers with the zero dispersion wavelengths (ZDW) close to the pump wavelength are presented. The first MOF is an endlessly singlemode fiber with normal dispersion at the pump wavelength, while the second fiber is a large air-filling fraction MOF with anomalous dispersion at 1064 nm.
Upconversion luminescence in erbium doped transparent oxyfluoride glass ceramics containing hexagonal NaYF4 nanocrystals
2015
Abstract In this work transparent erbium doped oxyfluoride glass ceramics containing hexagonal NaYF 4 nanocrystals has been prepared by melt-quenching and subsequent heat treatment of the precursor glass. The formation of β-NaYF 4 was confirmed by X-ray diffraction measurements. The overall intensity of the upconversion luminescence of the glass ceramics sample is 2 orders of magnitude higher than that of the precursor glass. The observed enhancement of the efficiency is explained by the incorporation of Er 3+ into low-phonon β-NaYF 4 crystalline phase.
Studies of radiation defects in cerium, europium and terbium activated oxyfluoride glasses and glass ceramics
2015
Abstract Terbium, cerium and europium activated oxyfluoride glasses and glass ceramics have been studied by thermally stimulated luminescence (TSL) and optical absorption techniques after the X-ray irradiation. A creation of colour centres in oxyfluoride glass matrix and TSL peaks depending on the activator type were observed. LaF 3 and rare earth activators were analysed by SEM–EDS.
EPR characterization of erbium in glasses and glass ceramics
2020
Electron paramagnetic resonance (EPR) is a well-established spectroscopic technique for electronic structure characterization of rare-earth ion impurities in crystalline and amorphous hosts. EPR spectra of erbium-doped glass matrices and nanocomposites can provide information about local structure variations induced by changes in chemical composition or crystallization processes. Characterization possibilities of Er3+ ions in glasses and glass ceramics including direct EPR measurements, indirect investigations via secondary paramagnetic probes, and optically detected magnetic resonance techniques are considered in this article. ----/ / /---- This is the pre-print of the following article: A…