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Showing 1 to 20 of 122 for “"femtosecond laser"”.
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Femtosecond laser writing in transparent materials
… in high index bismuth borate glass by femtosecond laser direct writing. Broadening of the transmitted light source by as much as 500 nm was demonstrated through a waveguide with a length of 1.8 cm. Finally, passive waveguide components such as Y-splitters and directional couplers have …
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Femtosecond-Laser-Enabled Fiber-Optic Interferometric Devices
During the past decades, femtosecond laser micro-fabrication has gained growing interests owing to its several unique features including direct and maskless fabrication, flexible choice of materials and geometries, and truly three-dimensional fabrication. Moreover, fiber-optic sensors have …
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Applications of femtosecond laser pulses in refractive eye surgery /
… for treatment of refractive errors is the laser-assisted in situ keratomileusis. The main goal of this work is to explore the possibility to replace two different laser systems (UV nanosecond and nIR femtosecond), that are currently used for the refractive corneal surgery, with a single …
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Measuring the Frequency of Light using Femtosecond Laser Pulses
… combs generated by the periodic pulse trains of femtosecond lasers. The output spectrum of such a laser consists of modes equally spaced by the repetition frequency of the pulses and forms a convenient ruler in frequency space. Extending this principle to the intervals between harmonics of the …
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Fiber inline pressure and acoustic sensor fabricated with femtosecond laser
… for harsh environment applications through femtosecond laser fabrication. Working towards this objective, the dissertation explored two types of fiber inline microsensors fabricated by femtosecond laser: an extrinsic Fabry-Perot interferometric (EFPI) sensor with silica diaphragm for …
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Femtosecond laser fabrication of directional couplers and Mach-Zehnder interferometers
The use of femtosecond lasers for photonic device fabrication in glass has become an active area of research in recent years. Since the first demonstration of laser modification of refractive index in glass, a variety of devices such as couplers, interferometers, gratings, 3D structures, active …
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Optical resistance of dielectric coatings to multi-pulse femtosecond laser radiation /
… the experimental and theoretical analysis of the femtosecond laser pulse induced damage processes in thin film dielectric coatings. Experimental investigations were performed by automated metrological facility designed for S-on-1 laser-induced damage threshold measurements. Femtosecond repetitive …
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Inscription of in-fibre photonic devices by an infrared femtosecond laser
… Bragg gratings using a tightly focused infrared femtosecond laser is implemented for the first time. Fibre Bragg gratings are wavelength-selective, retro-reflectors which have become a key component in optical communications as well as offering great potential as a sensing tool. Standard methods …
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Femtosecond laser studies of molecular wavepacket dynamics in the cesium dimer
Femtosecond laser pump-probe experiments have been applied to the study of vibrational wavepacket dynamics in the excited states of the cesium dimer, Cs$\sb2.$ The real-time vibrational motion of the molecule is observed by probing the quantum motion of the wavepacket on a potential surface by a …
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The mechanism of thin film Si nanomachining using femtosecond laser pulses
Femtosecond (fs) laser ablation has been the subject of intense recent research. The pulse time ('width') is shorter than the electronic relaxation time, resulting in a decoupling of the period of laser illumination and the melting of the substrate. Since the laser does not directly heat the …
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Crack Tip Micromaching by Femtosecond Laser for Fracture Testing of Metal Laminates
… experimental study of the effects of ultrafast laser ablation on the mechanical properties of metal laminates followed by FEA simulation to elucidate future experimental potential. The metals investigated are copper, niobium, and copper/niobium accumulative roll bonded (ARB) laminates. The two …
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Characterization and optimization of photonic devices fabricated using femtosecond laser micro-matching
… deal of interest and activity in the area of femtosecond micromachining of transparent materials. It promises to be a powerful technique for rapid fabrication of photonic devices in three dimensional geometries. Our group has fabricated and investigated an array of two dimensional and novel …
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Femtosecond laser micro-machining and consequent self-assembled nano-structures in transparent materials
… have reported novel developments in the field of femtosecond laser micro-machining within the bulk of transparent materials. Thanks to its unique properties, the femtosecond laser writing technique offers the potential for realizing three-dimensional multi-component photonic devices, fabricated in …
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Femtosecond-laser irradiation as a platform for tailoring the optoelectronic properties of silicon
… naturally transparent to light in the infrared. Femtosecond (fs) laser irradiation offers multiple unique approaches to improving the optoelectronic properties of silicon, enabling both thin-film silicon photovoltaics and silicon-based IR photodetectors. In this thesis I study the …
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Examining ablation efficiency in alumina ceramics utilizing femtosecond laser with mhz/ghz burst regime /
… processing, and limited processing accuracy. Laser processing has been integrated into industrial processes for some time due to its ability to process various materials, including ceramics, while avoiding the drawbacks of mechanical processing. Femtosecond laser processing is a suitable …
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Femtosecond Laser Interactions In The Condensed Phase: Application to Transient Absorption and Materials Processing
Solid State laser systems are now capable of generating temporal pulses of sub-10 fs duration and facilitate the study of ultrafast phenomena in chemical, biological and physical systems. The high field intensities inherent in these pulses, means that highly non-linear processes may be observed. …
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A Study of Infrared Femtosecond Laser Irradiation on Monolayer Graphene on SiO2/Si Substrate
… sensors. This thesis focuses on the femtosecond laser processing of graphene from both scientific and industrial points of view. Started from the manufacturing process, a new manufacturing route for graphene devices based on a femtosecond laser system is explored. In this thesis, the …
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