| 1. |
- Camara, A. R., et al.
(författare)
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LSPR-based fiber optic sensing with chemically deposited Au nanoparticles
- 2010
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Ingår i: Latin America Optics and Photonics Conference (LAOP) 2010. - Washington, D.C. : OSA. - 9781557529039
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Konferensbidrag (refereegranskat)abstract
- A refractive index fiber optic sensor based on Localized Surface Plasmon Resonance (LSPR) and specular reflection from chemically deposited gold nanoparticles has been characterized, presenting a sensitivity of 38 nm/RIU.
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| 2. |
- Ferraris, Sara, et al.
(författare)
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Chemical, mechanical and antibacterial properties of silver nanocluster/silica composite coated textiles for safety systems and aerospace applications
- 2014
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Ingår i: Applied Surface Science. - : Elsevier BV. - 0169-4332 .- 1873-5584. ; 317, s. 131-139
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Tidskriftsartikel (refereegranskat)abstract
- This work describes the chemical, mechanical and antibacterial properties of a novel silver nanocluster/silica composite coating, obtained by sputtering, on textiles for use in nuclear bacteriological and chemical (NBC) protection suites and for aerospace applications.The properties of the coated textiles were analyzed in terms of surface morphology, silver concentration and silver release in artificial sweat and synthetic tap water, respectively. No release of silver nanoparticles was observed at given conditions.The water repellency, permeability, flammability and mechanical resistance of the textiles before and after sputtering demonstrated that the textile properties were not negatively affected by the coating.The antibacterial effect was evaluated at different experimental conditions using a standard bacterial strain of Staphylococcus aureus and compared with the behavior of uncoated textiles.The coating process conferred all textiles a good antibacterial activity. Optimal deposition conditions were elaborated to obtain sufficient antibacterial action without altering the aesthetical appearance of the textiles.The antibacterial coating retained its antibacterial activity after one cycle in a washing machine only for the Nylon based textile.
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| 3. |
- Fokine, Michael, et al.
(författare)
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CO2 laser structuring of semiconductor-core glass fibers
- 2014
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Ingår i: Optics InfoBase Conference Papers. - : OSA - The Optical Society. - 9781943580194
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Konferensbidrag (refereegranskat)abstract
- A scanning CO2 laser system is used to process semiconductor core glass fibers. The conditions can be tuned to melt the core and soften the glass, producing resonators, tapers and bends.
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| 4. |
- Fokine, Michael, 1970-, et al.
(författare)
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Optical Characterization of Plasmonic Metamaterial Absorber
- 2010
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Konferensbidrag (refereegranskat)abstract
- A reflectance/transmittance experiment setup to characterize a sub-wavelength, wide-angle, ultrathin metamaterial absorber at optical frequency regime is shown, and the measured results are presented.
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| 5. |
- Fokine, Michael, 1970-, et al.
(författare)
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Spectral features of specular reflection from nanoparticle films
- 2010
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Ingår i: Physica Status Solidi. C, Current topics in solid state physics. - : Wiley. - 1610-1634 .- 1610-1642. ; 8:9, s. 2673-2675
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Tidskriftsartikel (refereegranskat)abstract
- In this work we analyze the internal reflection (Fresnel reflection) from Au nanoparticles on the end face of optical fibers. We demonstrate that changes in the refractive index of the surrounding medium can be detected by shifts in the reflection spectra associated with changes in the Localized Surface Plasmon Resonance of the Au-Nanoparticles. The spectral response is simulated using a model based on the interference in multilayer structures and can be described by transfer-matrix method.
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| 6. |
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| 7. |
- Gouvêa, P. M. P., et al.
(författare)
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Characterization of a fiber optic sensor based on LSPR and specular reflection
- 2010
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Ingår i: Optical Sensors (Sensors) 2010. - 9781557528964
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Konferensbidrag (refereegranskat)abstract
- A fiber optic sensor based on Localized Surface Plasmon Resonance (LSPR) and specular reflection has been characterized as a function of refractive índex. The sensitivity has been obtained for the range from n=1.0 to n=2.0.
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| 8. |
- Gouvea, Paula M. P., et al.
(författare)
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Internal specular reflection from nanoparticle layers on the end face of optical fibers
- 2011
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 109:10, s. 103114-
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Tidskriftsartikel (refereegranskat)abstract
- Metal nanoparticles deposited on a dielectric substrate exhibit an absorption peak due to localized surface plasmon resonance (LSPR). Changes in the refractive index of the surrounding medium cause the LSPR band to shift in wavelength. In this paper, gold nanoparticles were placed on the end face of an optical fiber spliced to a reflection setup. As expected in reflection geometries, the back-reflected signal exhibits a dip at wavelengths in the LSPR band when the fiber tip is surrounded by ambient air (n = 1). However, as the refractive index of the surrounding medium is increased, there is a gradual inversion from a dip (n = 1.0) to a peak (n = 2.0). To explain these results, a model based on absorption and interference between the specular reflections from the fiber/nanoparticle and nanoparticle/ambient interfaces is proposed, showing that our reflection configuration can be used in sensing applications.
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| 9. |
- Holmberg, Patrik, et al.
(författare)
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Chemical composition gratings
- 2014
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Ingår i: Specialty Optical Fibers, SOF 2014. - Washington, D.C. : Optical Society of America (OSA).
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Konferensbidrag (refereegranskat)abstract
- High-temperature stable fiber Bragg gratings will be reviewed with an emphasis on recent material studies using Chemical Composition gratings.
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| 10. |
- Holmberg, Patrik, et al.
(författare)
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Monitoring temperature in optical fibers during thermal processing
- 2013
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Ingår i: Optics InfoBase Conference Papers.
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Konferensbidrag (refereegranskat)abstract
- Temperature dynamics in optical fibers during CO2-laser irradiation, at temperatures above the softening point of fused silica, were characterized using chemical composition gratings. The technique offers possibilities for enhanced temperature control during optical fiber processing.
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| 11. |
- Holmberg, Patrik, 1971-, et al.
(författare)
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Study of incubation effects during surface ablation using picosecond pulses at a wavelength of 800 nm
- 2011
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Ingår i: Physica Status Solidi. C, Current topics in solid state physics. - Weinheim : WILEY-VCH Verlag GmbH & Co. - 1610-1634 .- 1610-1642. ; 8:9, s. 2862-2865
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Tidskriftsartikel (refereegranskat)abstract
- A comparison of laser ablation on the front-surface (surface facing the laser) and back-surface of 1.1 mm thick boro-aluminosilicate glass plates has been performed using 1 ps pulses at a wavelength of 800 nm. The resulting structures of front- and back-surface ablation are compared relative to an input design geometry of 40 µm deep and 40 µm wide surface channels. The influence of incubation effects on the final structure is discussed.
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| 12. |
- Holmberg, Patrik, 1971-, et al.
(författare)
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Thermometric study of CO2-laser heated optical fibers in excess of 1700 degrees C using fiber Bragg gratings
- 2013
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Ingår i: Journal of the Optical Society of America. B, Optical physics. - 0740-3224 .- 1520-8540. ; 30:7, s. 1835-1842
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Tidskriftsartikel (refereegranskat)abstract
- The thermal response of optical fibers during CO2 laser irradiation has been characterized by using thermally stable short-period fiber Bragg gratings, referred to as chemical composition gratings. CO2 laser beam profiling was performed by scanning the beam across a 1 mm long grating, providing a spatial resolution given by the fiber diameter. The thermal dynamics during square pulse irradiation has been recorded for temperatures in excess of 1700°C, with heating and cooling rates as high as 10,500°C s−1 and 6500°C s−1, respectively.
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| 13. |
- Holmberg, Patrik, 1971-, et al.
(författare)
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Using Fiber Bragg Gratings to measure temperatures up to 2000 K
- 2012
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The thermal response of optical fibers during CO2 laser irradiation with a wavelength of 10.6 µm has been characterized by use of thermally stable short period fiber Bragg gratings, referred to as chemical composition gratings.Beam profiling of the collimated beam from a CO2laser having a 1/e2 diameter of ~6.5 mm, was performed with a spatial resolution given by the fiber diameter. Heating- and cooling-dynamics of the fiber irradiated with a square pulse with a 1/e rise time of < 1 ms were performed with a temporal resolution down to~250 µs, for temperatures in excess of 1700 ºC.
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| 14. |
- Romani, E. C., et al.
(författare)
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Gold nanoparticles on the surface of soda-lime glass : morphological, linear and nonlinear optical characterization
- 2012
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Ingår i: Optics Express. - 1094-4087. ; 20:5, s. 5429-5439
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Tidskriftsartikel (refereegranskat)abstract
- Materials presenting high optical nonlinearity, such as materials containing metal nanoparticles (NPs), can be used in various applications in photonics. This motivated the research presented in this paper, where morphological, linear and nonlinear optical characteristics of gold NPs on the surface of bulk soda-lime glass substrates were investigated as a function of nanoparticle height. The NPs were obtained by annealing gold (Au) thin films previously deposited on the substrates. Pixel intensity histogram fitting on Atomic Force Microscopy (AFM) images was performed to obtain the thickness of the deposited film. Image analysis was employed to obtain the statistical distribution of the average height of the NPs. In addition, absorbance spectra of the samples before and after annealing were measured. Finally, the nonlinear refractive index (n(2))and the nonlinear absorption index (alpha 2) at 800 nm were obtained before and after annealing by using the thermally managed eclipse Z-scan (TM-EZ) technique with a Ti: Sapphire laser (150 fs pulses). Results show that both n2 and alpha 2 at this wavelength change signs after the annealing and that the samples presented a high nonlinear refractive index.
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| 15. |
- Zukauskas, Andrius, 1983-, et al.
(författare)
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Fabrication of submicrometer quasi-phase-matched devices in KTP and RKTP [Invited]
- 2011
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Ingår i: Optical Materials Express. - : Optical Society of America. - 2159-3930. ; 1:7, s. 1319-1325
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Tidskriftsartikel (refereegranskat)abstract
- We review the techniques used for fabrication of bulk submicrometer ferroelectric domain gratings in KTiOPO4 (KTP) and demonstrate that bulk Rb-doped KTiOPO4 (RKTP) is an excellent candidate for implementation of dense domain gratings. Compared to KTP, RKTP presents predominant domain propagation along the polar c-direction, substantially reduced lateral domain broadening, and higher poling yield. As a result we obtain homogeneous sub-μm periodic poling of RKTP with a period of 690 nm in 1 mm thick samples.
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