Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Proceed order?

Export
Filter
Collection
Keywords
Publisher
Years
  • 1
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Optical Materials 3 (1994), S. 243-250 
    ISSN: 0925-3467
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 55 (1992), S. 114-118 
    ISSN: 1432-0630
    Keywords: 42.40 ; 42.70 ; 78.20
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Light-induced refractive index changes in LiNbO3:Fe crystals are investigated at high light intensities (〉109 Wm−2). Holographic gratings are recorded and erased with frequency-doubled pulses of a Q-switched Nd:YAG laser. We find new intensity dependent contributions to the holographic sensitivity, to the photoconductivity, and to the saturation value of refractive index change. Light-induced absorption changes are also detected. These results indicate that the Fe2+/Fe3+ charge transport model, well established for low intensities, has to be modified for high intensities by assuming additional centers which trap and supply electrons.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1432-0630
    Keywords: 72.20 ; 72.40 ; 78.30
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract We report on a detailed investigation (EPR, SHG, optical absorption, luminescence and Raman scattering) on the new damage-resistant impurity indium in LiNbO3, where the increased photoconductivity strongly reduces the photorefractive effect. EPR and optical absorption measurements point to a complete disappearance of the Nb antisite in LiNbO3: In for all In concentrations. We believe that the very effective driving out of Nb antisites by In is due to the trivalent charge state of In and the possibility of charge self-compensation. Similarities in the properties of Mg-, Zn- or Indoped samples are discussed. Simultaneous doping with In and Zn leads to an addition of both contributions, in particular for optical frequency doubling and luminescence. Raman studies prove that In does not improve the stoichiometry of the crystals. Indium doping provides the possibility to control simultaneously phase-matching conditions and to reduce drastically photorefraction. Therefore, In co-doped LiNbO3 compositions are promising materials for applications after solving contemporary growth problems.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1432-0630
    Keywords: 77.80.−e ; 76.30.Fc ; 61.50.Cj ; 78.20.Jq
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract The growth of LiNbO3 single crystals from a melt with the Li/Nb ratio of 0.946, to which 6 wt.% K2O has been added, leads to stoichiometric specimens, essentially free of potassium, with (50±0.15) mol% Li2O in the crystal. This is established by studying the composition dependence of the following properties: linewidths of the electron paramagnetic resonance (EPR) of Fe3+, energy of the fundamental absorption edge, Raman linewidths of phonon modes, and dispersion of the optical birefringence. Comparison of the results with relevant calibration scales leads to the above composition. In all cases the Li2O content was found to be closer to 50% than that of a LiNbO3 crystal vapor-phase equilibrated to 49.9mol% Li2O. The photorefractive effect at light intensities I≥107 W/m2 is suppressed in this stoichiometric material. The features of the ternary system K2O-Li2O-Nb2O5, which are possibly responsible for the unexpected growth of stoichiometric LiNbO3 from the indicated melts, are discussed.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 58 (1994), S. 191-195 
    ISSN: 1432-0630
    Keywords: 42.40 ; 78.20 ; 61.70
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Holograms may be recorded in photorefractive LiNbO3:Cu with pulsed infrared light (wavelength λ=1064 nm, Q-switched Nd:YAG laser), if the crystals are previously or simultaneously illuminated with a green (λ=532 nm) light pulse. We study refractive index changes and time constants of as-grown and thermally treated crystals with different copper concentrations. A model explaining this effect is discussed.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 59 (1994), S. 437-443 
    ISSN: 1432-0649
    Keywords: 65.90 ; 72.20 ; 78.20
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Holographic gratings are recorded in LiNbO3: Fe using frequency-doubled pulses of aQ-switched Nd : YAG laser (light wavelengthλ = 532 nm, pulse durationt p = 20ns). We monitor diffraction efficiencies of the holograms during and several milliseconds after exposure. Variations of Fe2+ concentration, light intensity, and fringe spacing show that different types of gratings are involved: photochromic, thermooptic, pyroelectric, and space-charge gratings. The influence of the internal pyroelectric field on the light-induced charge transport is discussed in terms of a two-center model. Pyroelectric and bulk photovoltaic effect are shown to partially compensate each other. In LiNbO3: Fe, the photovoltaic effect is the dominant charge-driving force for our recording conditions.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 61 (1995), S. 89-93 
    ISSN: 1432-0649
    Keywords: 61.70 ; 72.20 ; 78.20
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract In LiNbO3:Fe,Me crystals (Me = K, Mg, Zn) elementary holograms are recorded and erased with frequency-doubled, ordinarily polarized pulses of a Q-switched Nd:YAG laser. At high light intensities (I 〉 109 Wm−2) holographic sensitivities and saturation values of refractive index changes grow with increasing intensity and a contribution to photo-conductivity appears increasing quadratically withI. The intensity-dependent parts of the holographic quantities are diminished by increasing the lithium content of the samples or by doping the crystals with magnesium or zinc. Experimental results can be described by a two-center charge transport model, which is the Fe2+/3+ model supplemented by shallow traps, namely niobium ions occupying lithium sites.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...