Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 14 of 14 for “"Nonlinear absorption"”.
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Modeling of photocurrent spectra induced by nonlinear absorption in high-indium-content iii-nitride disk-in-wire photodiode
Research on semiconductor quantum structures has raised many interesting questions about fundamental physics and potential applications in many fields. By utilizing the physical properties induced by quantum structure in semiconductors, which depend on the dimension of the systems, one can gain …
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Experimental Techniques For Nonlinear Material Characterization: A Nonlinear Spectrometer Using A White-light Continuum Z-scan
… a new method for the rapid determination of the nonlinear absorption spectra and the dispersion of the nonlinear refraction of optical materials in the visible and near IR spectral regions. However, conventional methods like, white-light continuum pump-probe and Z-scan techniques were used to …
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Amorphous silica-based carbon nanotube and silver nanoprism coatings: synthesis and investigation of their optical properties /
… is obtained with surfactant P4VP. Saturable absorption experiments showed better performance of semiconductive SWCNT compared to unsorted ones – they have lower non-saturable loses and lower saturation power. SWCNT-silica composite coatings show higher thermal stability compared to polymeric …
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Optomechanical Spin-Photon Interface in Wide-Bandgap Materials
… loss rate if the material platform suffers from nonlinear absorption. As a result, this thesis employs wide-band gap materials, such as diamond and hexagonal boron nitride (hBN), which exhibit negligible nonlinear absorption at telecommunication wavelengths. In this thesis, we demonstrate an …
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Modified chalcogenide glasses for optical device applications
… Tunnelling has been identified as the dominant nonlinear absorption mechanism in the formation of the waveguides. Single mode guidance at 633 nm has been demonstrated. The writing parameters for the minimum propagation loss of 1.47 dB/cm are 0.36 µJ pulse energy and 50 µm/s scanning speed. The …
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Nonlinear optical properties of novel nanostructured ion implanted laser ablated silicon using femtosecond pulse excitation
The study of the nonlinear optical properties of novel nanostructured ion implanted and laser ablation of Silicon is motivated by the need for materials that exhibit large values of the real part of the third order nonlinear susceptibility ([chi]^{(3)}_{Re}). This property is essential for light …
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Measuring Nonlinear Properties of Graphene Thin Films Using Z-Scan Technique
<p>The nonlinear studies of two-dimensional (2D) nanomaterials, specifically graphene, are very significant since graphene is finding its usefulness in handling the enormous heat in nanoscale high-density power electronics. Graphene has emerged to be a promising nanomaterial as an excellent heat …
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Nonlinear optical properties of natural dyes based on optical resonance
… natural dyes remain essential for the large nonlinear absorption expressed in terms of nonlinear optical susceptibilities or other mechanism of absorption such as two photon absorption (TPA), reverse saturable absorption (RSA) or intensitydependent refractive index characteristic. In this …
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Time domain measurement of the nonlinear refractive index in optical fibers and semiconductor film
A new technique to measure the nonlinear refractive index n_2 in optical fibers and semiconductor films has been developed. It is based on the time delay two-beam coupling of very intense picosecond laser pulses that have been self-phase modulated in the nonlinear optical medium. The two beams are …
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Resonant photonic crystal photodetectors for the infrared in silicon
… CMOS processes; silicon's lack of strong absorption at the wavelengths of interest makes this challenging. The approach uses defect-state mediated linear absorption and two-photon absorption (TPA) in small mode-volume resonators to generate photocarriers. Such resonators allow efficient …
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Nonlinear Optics in III-V Quaternary Semiconductor Waveguides
… there is still lack of data in literature on nonlinear optical properties of these materials. In this thesis, we extend the quest to evaluate more candidates from this class of semiconductors. Moreover, we are aiming for demonstrating the potentials of various III-V compounds for nonlinear …
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Study of Linear and Nonlinear Optical Interactions of Micro/Nanoparticles Embedded in an Organosiloxane Matrix
… candidate for a solar reflective coating. Strong nonlinear scattering, together with strong broadband and specific wavelength absorption properties, make GO and AgNPs excellent options for optical limiting devices, which have a high optical transmittance for normal light, but allow a significantly …
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Optical properties and thermal conductivity of resistive Au nanogranular films
… nanogranular gold films, namely their linear and nonlinear optical properties and their thermal conductivity. The linear optical properties were observed using femtosecond transient absorption spectroscopy (fTAS) and their film morphology was explored with atomic force microscopy. The switch …
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Three-photon Absorption Process In Organic Dyes Enhanced By Surface Plasmon Resonance
Multi-photon absorption processes have received significant attention from the scientific community during the last decade, mainly because of their potential applications in optical limiting, data storage and biomedical fields. Perhaps, one of the most investigated processes studied so far has been …