Search results for "Refractive index contrast"

showing 2 items of 2 documents

Near-field scanning optical microscopy to study nanometric structural details of LiNbO3 Zn-diffused channel waveguides

2008

A near-field scanning optical microscope (NSOM) is used to perform structural and optical characterization of the surface layer after Zn diffusion in a channel waveguide fabricated on lithium niobate. A theoretical approach has been developed in order to extract refractive index contrast from NSOM optical transmission measurements (illumination configuration). As a result, different solid phases present on the sample surface can be identified, such as ZnO and ZnNb2O6. They appear like submicrometric crystallites aligned along the domain wall direction, whose origin can be ascribed to some strain relaxation mechanism during the annealing process after Zn diffusion. Jose.Canet-Ferrer@uv.es

Materials scienceLithium niobateRefractive indexGeneral Physics and AstronomyWaveguide (optics)law.inventionAnnealingchemistry.chemical_compoundAnnealing ; Crystallites ; Lithium compounds ; Nanostructured materials ; Near-field scanning optical microscopy ; Optical waveguides ; Refractive index ; StoichiometryOpticsOptical microscopelaw:FÍSICA [UNESCO]Refractive index contrastSurface layerNear-field scanning optical microscopyÓpticabusiness.industryUNESCO::FÍSICACrystallitesFísicaLithium compoundsNanostructured materialsStoichiometryOptical waveguideschemistryNear-field scanning optical microscopeCrystallitebusinessRefractive index
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Near-IR- and UV-femtosecond laser waveguide inscription in silica glasses

2019

The influence of laser parameters on silica based waveguide inscription is investigated by using femtosecond laser pulses at 1030 nm (near-IR) and at 343 nm (UV). Negative phase contrast microscopy technique is used to measure the refractive index contrast for different photo-inscribed waveguides and shows the effects of both laser wavelength and scanning speed. In particular, UV photons have a higher efficiency in the waveguide production process as also confirmed by the lower optical losses at 1550 nm in these waveguides. These measurements are combined with micro-Raman and photoluminescence techniques, highlighting that laser exposure induces both structural modification of the silica an…

Materials sciencePhotoluminescenceLaser scanning02 engineering and technologyLaser waveguide inscriptionSilica glasse01 natural scienceslaw.invention010309 opticslaw0103 physical sciencesMicroscopyRefractive index contrastbusiness.industry021001 nanoscience & nanotechnologyLaserUltrashort laser pulseElectronic Optical and Magnetic Materialsphotoluminescence spectroscopyFemtosecondRaman spectroscopyOptoelectronics0210 nano-technologybusinessRefractive indexWaveguide
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