Hybrid organic-inorganic waveguides based on ZnO-(3-glycidoxypropil)trimethoxisilane (GPTS) have been fabricated by sol-gel route. A transparent sol of ZnO was added to the GPTS host and the resulting sol was deposited on silica substrates by spin coating technique. Waveguides with different molar composition (100-x)GPTS-xZnO (x=10, 20, 30) were investigated by different diagnostic techniques. Morphological measurements were carried out by means of an AFM apparatus, and a roughness of few nanometers was determinate for all the waveguides. Optical properties such as refractive index, thickness, number of propagating modes and attenuation coefficient were measured at 632.8, 543.5, 1319 and 1542 nm by the prism coupling technique as a function of the ZnO content. Photoluminescence measurements showed a large luminescence band in the region between 350 nm to 600 nm with a main peak centred at about 380 nm, due to the presence of ZnO nanoparticles.

Waveguide

Nanometre

Characterization

Spin Coating

10.1117/12.781197

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Citations (1)

Efficient visible up-conversion emission in Pr³⁺- and Er³⁺-doped aluminum fluorophospate glasses

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE (2000)

V. K. Tikhomirov Raffaella Rolli M. Montagna Maurizio Ferrari Animesh Jha

Intense upconversion of yellow-to-blue, in Pr³⁺- doped, and green-to-blue in Er³⁺-doped aluminum fluoride glasses is reported. Pulsed excitations inside the ³H₄ yields ¹D₂ absorption band of Pr³⁺ results in blue emission which is ascribed to the ³P₀ yields ³H₄ transition. We found that the temporal evolution of the upconverted fluorescence is characterized by rise and decay times depending on Pr³⁺ concentration. The upconversion mechanism is a two step process due to the energy transfer involving a pair of Pr³⁺ ions. The data indicate a high solubility of the Pr³⁺ ions without clustering at the doping level between 0.1 - 1% mol Pr³⁺. Measurements performed in Er³⁺doped glasses indicate a good quantum yield of the upconversion emission confirming the high solubility of Er³⁺ ions in the aluminum fluoride glasses.

Photon Upconversion

10.1117/12.382856

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Citations (3)

Design of an Efficient Pumping Scheme for Mid-IR Dy³⁺:Ga₅Ge₂₀Sb₁₀S₆₅ PCF Fiber Laser

IEEE Photonics Technology Letters (2016)

Mario Christian Falconi Giuseppe Palma Florent Starecki Virginie Nazabal J. Troles

This letter illustrates the design of a novel medium infrared (Mid-IR) laser based on a photonic crystal fiber made of dysprosium-doped chalcogenide glass, Dy ³⁺ :Ga ₅ Ge ₂₀ Sb ₁₀ S ₆₅ . In order to perform a realistic investigation, the simulation is performed by taking into account the spectroscopic parameters measured on the rare earth-doped glass sample. The simulated results show that an optical beam emission close to 4400-nm wavelength can be obtained by employing two pump beams at 2850 nm (pump #1) and 4092 nm (pump #2) wavelengths. The pump beams can be provided by commercial quantum cascade lasers. As example, for the pump powers of 50 mW (pump #1) and 1 W (pump #2), the input mirror reflectivity of 99%, the output mirror reflectivity of 30%, and the optical cavity length of 50 cm, a signal power close to 350 mW at the wavelength of 4384 nm can be generated. This result indicates that the designed source configuration is feasible for high beam quality Mid-IR light generation and it is efficient enough to find applications in optical free propagation links, optical remote sensing, and medicine.

10.1109/lpt.2016.2581022

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Citations (66)

About the Implementation of Frequency Conversion Processes in Solar Cell Device Simulations

Micromachines (2018)

Alexander Quandt Tahir Aslan Itumeleng Mokgosi Robert Warmbier Maurizio Ferrari

Solar cells are electrical devices that can directly convert sunlight into electricity. While solar cells are a mature technology, their efficiencies are still far below the theoretical limit. The major losses in a typical semiconductor solar cell are due to the thermalization of electrons in the UV and visible range of the solar spectrum, the inability of a solar cell to absorb photons with energies below the electronic band gap, and losses due to the recombination of electrons and holes, which mainly occur at the contacts. These prevent the realization of the theoretical efficiency limit of 85% for a generic photovoltaic device. A promising strategy to harness light with minimum thermal losses outside the typical frequency range of a single junction solar cell could be frequency conversion using rare earth ions, as suggested by Trupke. In this work, we discuss the modelling of generic frequency conversion processes in the context of solar cell device simulations, which can be used to supplement experimental studies. In the spirit of a proof-of-concept study, we limit the discussion to up-conversion and restrict ourselves to a simple rare earth model system, together with a basic diode model for a crystalline silicon solar cell. The results of this show that these simulations are very useful for the development of new types of highly efficient solar cells.

Multiple exciton generation

Thermalisation

10.3390/mi9090435

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Citations (7)

Optical and spectroscopic characterization of Er/Yb-activated planar waveguides

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE (2000)

S. Pelli M. Brenci Matteo Fossi Giancarlo C. Righini C. Duverger

Soda-lime silicate glasses doped with different percentages of Er- and Yb-oxides were produced by melting, and both planar and channel waveguides were fabricated by diluted silver ion exchange. Their optical and spectroscopic properties have been investigated, and some results are reported here. The optical parameters such as refractive index, diffusion depth and number of modes were measured by m-line technique. Absorption and fluorescence spectra were also measured; particular attention was focused on upconversion phenomena. The upconversion luminescence spectra of an Er/Yb-activated waveguide were obtained by continuous-wave excitation at 514.5 nm, as a function of the excitation power. The weak upconversion bands are assigned to the ²H_9/2 yields ⁴I_15/2 and ⁴G_11/2 yields ⁴I_15/2 transitions of the Er³⁺ ion. The upconversion mechanism is found to be a two-photon process. Preliminary results of gain measurements in channel waveguides showed signal enhancement at 1.5 micrometers , for high input signal intensities, upon pumping at 0.98 micrometers .

Photon Upconversion

Erbium

Ytterbium

Waveguide

10.1117/12.382851

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Citations (3)

Raman Scattering on the <i>l</i>=2 Spheroidal Mode of Spherical Nanoparticles

Advances in science and technology (2008)

D. Ristić Mile Ivanda K. Furić M. Montagna Maurizio Ferrari

Mode (computer interface)

10.4028/3-908158-12-5.132

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Citations (0)

Sol–gel-derived photonic structures: fabrication, assessment, and application

Journal of Sol-Gel Science and Technology (2011)

Andrea Chiappini Alessandro Chiasera Simone Berneschi Cristina Armellini Alessandro Carpentiero

Structural Coloration

Waveguide

10.1007/s10971-011-2556-y

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Citations (59)

Effects of Tm³⁺ Additions on the Crystallization of LaF₃ Nanocrystals in Oxyfluoride Glasses: Optical Characterization and Up‐Conversion

Journal of the American Ceramic Society (2012)

A. Martín Davor Ristić Somnath Bhattacharyya Thomas Höche Glenn C. Mather

The influence of the addition of 1 mol% Tm 2 O 3 on the nanocrystallization of LaF 3 in a glass of composition 55 SiO 2 –20 Al 2 O 3 –15 Na 2 O –10 LaF 3 (mol%) has been studied. Tm 2 O 3 affects the phase separation in the glass and delays the onset of crystallization with respect to the undoped glass. Additionally, the maximum LaF 3 crystal size is slightly greater than that in the undoped glass–ceramics. The microstructural and compositional changes in the glass matrix have been studied using several techniques, including viscosity, dilatometry, X‐ray and neutron diffraction ( XRD , ND ), quantitative Rietveld refinement, transmission electron microscopy ( TEM ), differential scanning calorimetry ( DSC ), and Raman spectroscopy. Photoluminescence measurements indicate that the Tm 3+ ions are distributed between the glassy matrix and LaF 3 crystals. Eu 2 O 3 has been used as structure probe and part of the Eu 3+ ions are reduced to Eu 2+ when incorporated in the LaF 3 nano‐crystals. Up‐conversion spectra under IR ‐excitation show a higher intensity of the blue emission in the Tm ‐doped glass–ceramic compared with that in the glass.

Glass-ceramic

10.1111/jace.12120

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Citations (52)

Up- and down-conversion in Yb3+–Pr3+ co-doped fluoride glasses and glass ceramics

Journal of Non-Crystalline Solids (2013)

B. Dieudonné B. Boulard G. Alombert-Goget Alessandro Chiasera Y. Gao

Ytterbium

10.1016/j.jnoncrysol.2012.12.025

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Citations (45)

Laser micro-sphérique en verre oxyde dopé Erbium