Browsing by Author "Othonos, Andreas S."
Now showing items 21-40 of 156
-
Article
Distributed strain measurement based on a fiber Bragg grating and its reflection spectrum analysis
LeBlanc, M.; Huang, S. Y.; Ohn, M.; Measures, R. M.; Guemes, A.; Othonos, Andreas S. (1996)A method of extracting the strain profile along a fiber Bragg grating from the intensity reflection spectrum is described. The procedure is based on a filter synthesis theory that relates the aperiodicity of a grating with ...
-
Article
Effects of Ge concentration, boron co-doping, and hydrogenation on fiber bragg grating characteristics
Konstantaki, M.; Tamiolakis, Q.; Argyris, A.; Othonos, Andreas S.; Ikiades, A. (2005)In this paper, we compare photosensitivity, refractive-index modulation depth, spectral bandwidth, and excess loss through the inscription of fiber Bragg gratings in unloaded and hydrogen-loaded fibers with low- or ...
-
Article
Electrical, structural, and optical properties of sulfurized Sn-doped In2O3 nanowires
Zervos, Matthew; Mihailescu, C. N.; Giapintzakis, Ioannis; Othonos, Andreas S.; Travlos, A.; Luculescu, C. R. (2015)Sn-doped In2O3 nanowires have been grown on Si via the vapor-liquid-solid mechanism at 800 °C and then exposed to H2S between 300 to 600 °C. We observe the existence of cubic bixbyite In2O3 and hexagonal SnS2 after processing ...
-
Article
Ellipsometric analysis of ion-implanted polycrystalline silicon films before and after annealing
Lioudakis, Emmanouil E.; Nassiopoulou, Androula Galiouna; Othonos, Andreas S. (2006)A study of arsenic ion-implanted polycrystalline silicon films before and after annealing at various temperatures has been performed using spectroscopic ellipsometry in the ultraviolet to the visible spectral region. Using ...
-
Article
Ellipsometry on optically thin palladium films on silicon-based substrate: Effects of low concentration of hydrogen
Lioudakis, Emmanouil E.; Othonos, Andreas S. (2005)Optically thin palladium films evaporated on silicon substrates are investigated following exposure to low concentrations of hydrogen gas in nitrogen using spectroscopic ellipsometry. Changes in the parameters tan Ψ and Δ ...
-
Article
Enhanced growth and photoluminescence properties of SnxN y (x>y) nanowires grown by halide chemical vapor deposition
Zervos, Matthew; Othonos, Andreas S. (2011)Tin nitride nanowires have been grown by halide chemical vapor deposition via the reaction of Sn with NH4Cl at 425 °C under a steady flow of NH3 using small ramp rates y) with a hexagonal structure, i.e. c=5.193 , a=3.725 ...
-
Article
Erratum: "Probing ultrafast carrier and phonon dynamics in semiconductors" [J. Appl. Phys. 83, 1789 (1998)]
Othonos, Andreas S. (1998)
-
Article
Excitation dynamics of a low bandgap silicon-bridged dithiophene copolymer and its composites with fullerenes
Othonos, Andreas S.; Itskos, Grigorios; Neophytou, Marios; Choulis, Stelios A. (2012)We report on excitation dynamics in pristine and bulk heterojunction films of the low bandgap silicon-bridged dithiophene copolymer poly[(4,4′-bis(2- ethylhexyl)dithieno[3,2-b:2′, 3′-d]silole)-2,6-diyl-alt-(4,7-bis(2- ...
-
Article
Femtosecond carrier dynamics in implanted and highly annealed polycrystalline silicon
Lioudakis, Emmanouil E.; Nassiopoulou, Androula Galiouna; Othonos, Andreas S. (2006)We have studied the ultrafast optical response of highly implanted and highly annealed polycrystalline silicon films using 400 nm ultrashort amplified pulses with fluence ranging between 8 mJ cm-2 to 56 mJ cm -2. Transient ...
-
Article
Femtosecond carrier dynamics in In 2O 3 nanocrystals
Othonos, Andreas S.; Zervos, Matthew; Tsokkou, Demetra (2009)We have studied carrier dynamics in In 2O 3 nanocrystals grown on a quartz substrate using chemical vapor deposition. Transient differential absorption measurements have been employed to investigate the relaxation dynamics ...
-
Article
Femtosecond carrier dynamics of Inx Ga1-x N thin films grown on GaN (0001): Effect of carrier-defect scattering
Lioudakis, Emmanouil E.; Othonos, Andreas S.; Iliopoulos, Eleftherios; Tsagaraki, K.; Georgakilas, A. (2007)Ultrafast carrier dynamics in ultrathin Inx Ga1-x N ternary alloys were investigated in detail, using femtosecond transient differential optical absorption measurements. Measurements were performed with probing wavelengths ...
-
Article
Femtosecond dynamics in single wall carbon nanotube/poly(3-hexylthiophene) composites
Lioudakis, Emmanouil E.; Othonos, Andreas S.; Alexandrou, Ioannis (2008)Femtosecond transient absorption measurements on single wall carbon nanotube/poly(3-hexylthiophene) composites are used to investigate the relaxation dynamics of this blended material. The influence of the addition of ...
-
Conference Object
Femtosecond laser inscription of Bragg and complex gratings in coated and encapsulated silica and low-loss polymer optical fibers
Kalli, Kyriacos; Lacraz, A.; Polis, M.; Othonos, Andreas S. (SPIE, 2015)The development of wavelength filters, such as Bragg and superstructure gratings in glass and polymer optical fibers, using a femtosecond laser is reported. By using a femtosecond laser operating in the green, which offers ...
-
Article
Femtosecond time-resolved study in InxGa1-xN (0001) ultrathin epilayers: Effects of high indium mole fraction and thickness of the films
Lioudakis, Emmanouil E.; Othonos, Andreas S.; Dimakis, Emmanouil; Georgakilas, A. (2006)In view of promising full-solar-spectrum photovoltaic systems based on Inx Ga1-x N ternary alloys, femtosecond time-resolved study in ultrathin epilayers was employed in order to extract the fundamental properties of ...
-
Article
Fiber Bragg gratings
Othonos, Andreas S. (1997)Since the discovery of photosensitivity in optical fibers there has been great interest in the fabrication of Bragg gratings within the core of a fiber. The ability to inscribe intracore Bragg gratings in these photosensitive ...
-
Book
Fiber Bragg gratings fundamentals and applications in telecommunications and sensing
Othonos, Andreas S.; Kalli, Kyriacos (Artech House, 1999)
-
Conference Object
Fiber Bragg-grating-based laser sensor
Wallace, Colin G.; Othonos, Andreas S.; Uttamchandani, Deepak G. (1995)Fiber Bragg gratings are attracting increasing attention as sensors for the measurement of strain, temperature, and pressure. They are equally important as wavelength selective reflectors for fiber, and to a lesser extent, ...
-
Conference Object
Fiber laser sensor array
Alavie, A. Tino; Karr, Shawn E.; Othonos, Andreas S.; Measures, Raymond M. (Publ by Society of Photo-Optical Instrumentation Engineers, 1993)An intracore Bragg grating and a broadband reflector are used as cavity end mirrors of a tunable Erbium-doped fiber laser where the Bragg grating serves the dual purpose of the tuning element and the sensor. This fiber ...
-
Article
Fibre Bragg gratings
Othonos, Andreas S.; Kalli, Kyriacos; Pureur, D.; Mugnier, A. (2006)
-
Article
Fine art painting characterization by spectroscopic ellipsometry: Preliminary measurements on varnish layers
Christofides, Constantinos; Castellon, B.; Othonos, Andreas S.; Polikreti, Kyriaki; De Deyne, C. (2004)The long-term conservation of the original state of paintings requires high quality multi-spectral digital image technologies. CRISATEL Program addresses fine art professionals as primary end-users base. The analysis by ...