Structural and Optical Properties of Rare-Earth Doped Lithium Niobate Waveguides Formed by Mev Helium Implantation

1995 ◽  
Vol 396 ◽  
Author(s):  
B. Herreros ◽  
G. Lifante ◽  
F. CussÓ ◽  
A. Kling ◽  
J.C. Soares ◽  
...  
Keyword(s):  
Lithium Niobate ◽  
Rare Earths ◽  
Optical Waveguides ◽  
Bulk Material ◽  
High Energy ◽  
Structural And Optical Properties ◽  
Lattice Damage ◽  
Helium Implantation ◽  
Er Doped ◽  
Rare Earth Doped

AbstractResults of investigations of optical waveguides formed by high energy helium implantation into lithium niobate codoped with 5 mol% MgO and 1 mol% Tm3+ or 1 mol% Er3+ are reported. A comparative study of structural and luminescence properties between implanted and untreated samples has been performed by means of Rutherford backscattering (RBS) combined with channeling and photoluminescence methods, respectively in order to investigate residual lattice damage and the incorporation of the optical active rare earths. For the case of Tm a full substitutional incorporation on the lithium site and a high crystal quality in both bulk and implanted waveguide material has been found. For Er doped lithium niobate the channeling results show a fraction of Er randomly incorporated or forming precipitates and a deterioration of the waveguide's lattice. The optical investigations show in both cases only a slight broadening of the emission lines of the rare earths in the waveguides compared to the bulk material.

Subsurface Processing of Electronic Materials Assisted by Atomic Displacements

MRS Bulletin ◽  
1992 ◽  
Vol 17 (6) ◽  
pp. 47-51 ◽  
Author(s):  
J.S. Williams
Keyword(s):  
Optical Waveguides ◽  
Electronic Materials ◽  
High Energy ◽  
Early Years ◽  
Atomic Displacements ◽  
Implantation Damage ◽  
Ion Damage ◽  
Lattice Damage ◽  
And Control ◽  
Device Operation

In the early years of doping of semiconductors by ion implantation, atomic displacements and residual lattice damage were considered undesirable byproducts of an otherwise controllable doping process. Steps were taken to minimize disorder during implantation and/or to remove it as completely as possible during a subsequent annealing process. In many cases, such as boron- or phosphorus-implanted silicon, annealing temperatures exceeding 900°C were necessary to achieve the desirable electrical properties. Indeed, removal of implantation damage remains a crucial issue, particularly as device dimensions shrink and the need has arisen for substantially lower processing temperatures. The advent of high-energy (MeV) implantation in specific processing steps and the increasing use of more complex (often multilayer) compound semiconductors has added further to the need to understand and control ion damage and its annealing in semiconductors.Over the past decade, there has been a growing realization that implantation induced atomic displacements and defects can have significant advantages in processing. For example, it was realized early that ion damage, and resultant defect fluxes to and from lattice disruptions, can “getter” and trap undesirable impurities that would otherwise interfere with device operation. More recently, it has been possible to use ion beams to tailor damage structures and form amorphous-crystalline superlattices, to remove pre-existing damage and induce crystallization of amorphous layers at very low temperatures, to form ultrapure amorphous silicon for studying thermodynamic properties of this phase, or to mix films with semiconductors and form stable compounds such as silicides. Indeed, ion damage has been used to electrically isolate devices, to form optical waveguides and cavities, and to improve the junction properties of deeply doped layers. These issues are briefly reviewed in this article.

scholarly journals Rare Earth Doped Silica Optical Fibre Sensors for Dosimetry in Medical and Technical Applications

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
N. Chiodini ◽  
A. Vedda ◽  
I. Veronese
Keyword(s):  
Radiation Therapy ◽  
Rare Earth ◽  
Optical Fibre ◽  
Rare Earths ◽  
High Energy ◽  
Silica Matrix ◽  
Optical Fibres ◽  
General Description ◽  
Optical Fibre Sensors ◽  
Rare Earth Doped

Radioluminescence optical fibre sensors are gaining importance since these devices are promising in several applications like high energy physics, particle tracking, real-time monitoring of radiation beams, and radioactive waste. Silica optical fibres play an important role thanks to their high radiation hardness. Moreover, rare earths may be incorporated to optimise the scintillation properties (emission spectrum, decay time) according to the particular application. This makes doped silica optical fibres a very versatile tool for the detection of ionizing radiation in many contexts. Among the fields of application of optical fibre sensors, radiation therapy represents a driving force for the research and development of new devices. In this review the recent progresses in the development of rare earth doped silica fibres for dosimetry in the medical field are described. After a general description of advantages and challenges for the use of optical fibre based dosimeter during radiation therapy treatment and diagnostic irradiations, the features of the incorporation of rare earths in the silica matrix in order to prepare radioluminescent optical fibre sensors are presented and discussed. In the last part of this paper, recent results obtained by using cerium, europium, and ytterbium doped silica optical fibres in radiation therapy applications are reviewed.

scholarly journals High Pressure X-ray Diffraction as a Tool for Designing Doped Ceria Thin Films Electrolytes

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 724
Author(s):  
Sara Massardo ◽  
Alessandro Cingolani ◽  
Cristina Artini
Keyword(s):  
Thin Films ◽  
High Pressure ◽  
Rare Earth ◽  
Ionic Conductivity ◽  
Bulk Material ◽  
Threshold Temperature ◽  
Doped Ceria ◽  
X Ray Diffraction ◽  
X Ray ◽  
Rare Earth Doped

Rare earth-doped ceria thin films are currently thoroughly studied to be used in miniaturized solid oxide cells, memristive devices and gas sensors. The employment in such different application fields derives from the most remarkable property of this material, namely ionic conductivity, occurring through the mobility of oxygen ions above a certain threshold temperature. This feature is in turn limited by the association of defects, which hinders the movement of ions through the lattice. In addition to these issues, ionic conductivity in thin films is dominated by the presence of the film/substrate interface, where a strain can arise as a consequence of lattice mismatch. A tensile strain, in particular, when not released through the occurrence of dislocations, enhances ionic conduction through the reduction of activation energy. Within this complex framework, high pressure X-ray diffraction investigations performed on the bulk material are of great help in estimating the bulk modulus of the material, and hence its compressibility, namely its tolerance toward the application of a compressive/tensile stress. In this review, an overview is given about the correlation between structure and transport properties in rare earth-doped ceria films, and the role of high pressure X-ray diffraction studies in the selection of the most proper compositions for the design of thin films.

Er-doped and Er, Yb co-doped oxyfluoride glasses and glass–ceramics, structural and optical properties

2011 ◽  
Vol 33 (11) ◽  
pp. 1630-1637 ◽  
Author(s):  
Radosław Lisiecki ◽  
Elżbieta Augustyn ◽  
Witold Ryba-Romanowski ◽  
Michał Żelechower
Keyword(s):  
Optical Properties ◽  
Glass Ceramics ◽  
Structural And Optical Properties ◽  
Oxyfluoride Glasses ◽  
Er Doped ◽  
Co Doped

Optical absorption of rare-earth-doped BeF2 glasses

1986 ◽  
Vol 1 (1) ◽  
pp. 139-143
Author(s):  
P. A. Tick
Keyword(s):  
Optical Absorption ◽  
Rare Earths ◽  
Near Infrared ◽  
Light Transmission ◽  
Infrared Region ◽  
Optical Absorption Spectra ◽  
Intrinsic Attenuation ◽  
Optimum Wavelength ◽  
Near Infrared Region ◽  
Rare Earth Doped

BeF2 glasses are potentially useful materials for light transmission in the near infrared region of the spectrum. While the intrinsic attenuation of BeF2 is thought to be much lower than silica, the optimum wavelength will be further in the infrared, near 2.1 μ. In this spectral region impurities other than transition metals may be important—rare earths, for example. The data required to estimate the contributions to attenuation are normally not available; hence it is the purpose of the present work to provide that information. Using a binary BeF2/ThF4 glass, the optical absorption spectra of a number of rare earths are measured. The experimental procedures, optical spectra, and absorption strength are described.

scholarly journals Luminescence characteristics of rare-earth-doped barium hexafluorogermanate BaGeF6 nanowires: fast subnanosecond decay time and high sensitivity in H2O2 detection

RSC Advances ◽  
2018 ◽  
Vol 8 (69) ◽  
pp. 39296-39306 ◽  
Author(s):  
Gibin George ◽  
Machael D. Simpson ◽  
Bhoj R. Gautam ◽  
Dong Fang ◽  
Jinfang Peng ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earths ◽  
Decay Time ◽  
High Sensitivity ◽  
H2o2 Detection ◽  
Highly Sensitive ◽  
Inorganic Scintillators ◽  
Luminescence Characteristics ◽  
Rare Earth Doped

The decay time of BaGeF6 nanowires codoped with rare earths is found in the order of subnanoseconds, being one of the shortest decay time records from inorganic scintillators. Their luminescence emissions are highly sensitive for H2O2 detection.

Doping of GaN by ion implantation

2000 ◽  
Vol 650 ◽  
Author(s):  
Eduardo J. Alves ◽  
C. Liu ◽  
Maria F. da Silva ◽  
José C. Soares ◽  
Rosário Correia ◽  
...  
Keyword(s):  
Optical Properties ◽  
Ion Implantation ◽  
Room Temperature ◽  
Lattice Site ◽  
Helium Temperature ◽  
Site Location ◽  
Structural And Optical Properties ◽  
X Ray ◽  
Er Doped ◽  
Ion Implanted

ABSTRACTIn this work we report the structural and optical properties of ion implanted GaN. Potential acceptors such as Ca and Er were used as dopants. Ion implantation was carried out with the substrate at room temperature and 550 °C, respectively. The lattice site location of the dopants was studied by Rutherford backscattering/channeling combined with particle induced X-ray emission. Angular scans along both [0001] and [1011] directions show that 50% of the Er ions implanted at 550 oC occupy substitutional or near substitutional Ga sites after annealing. For Ca we found only a fraction of 30% located in displaced Ga sites along the [0001] direction. The optical properties of the ion implanted GaN films have been studied by photoluminescence measurements. Er- related luminescence near 1.54 μm is observed under below band gap excitation at liquid helium temperature. The spectra of the annealed samples consist of multiline structures with the sharpest lines found in GaN until now. The green and red emissions were also observed in the Er doped samples after annealing.

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