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 19 of 19 for “"diffractive optics"”.
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Diffractive optics for maskless lithography and imaging
… limits of nanolithography. In ZPAL, an array of diffractive lenses is used to form an array of spots on the substrate. Each spot is modulated independently by means of spatial-light modulators. This essentially creates a "parallel laserwriter". In addition, this lithography system can be …
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Photogating Effect and Diffractive Optics in Low-Dimensional Structures
… allows for the construction of very precise diffractive lenses. This work entails the fabrication and simulation of MLFZPs, which are useful in their ability to tune the wavelength and focal length of the lenses to strict parameters. In addition, it is shown that these devices may be …
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Development of terahertz diffractive optics and plasmon-phonon polaritonics components /
… imaging systems. Namely development of terahertz diffractive optics and variable frequency polaritonic infrared optical components is described. Development and performance of direct laser ablation fabricated multilevel phase Fresnel lenses and metal Soret zone plates for focusing of 0.6 and 4.7 …
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Micro-fabricated diffractive optics for quantum sensors and atomic clocks
… realisationof a cold-atom, atomic clock. Diffractive optics are used to address the size constraints of the typical laser cooling apparatus to facilitate a portable device. The design and measurement of a wide range of grating parameters, including period, duty cycle, etch depth, and …
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Alignment and actuation of compliant nanostructures and diffractive optics by inter-nanomagnet forces
… work shows the ability of nanomagnets to tune diffractive optical elements through deformation and actuation of nanostructured freestanding beams such as in a diffraction grating. This actuation combines the advantages of both analog and digital tuning techniques. For both applications, …
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Maskless nanolithography and imaging with diffractive optical arrays
… from a century-old tradition of refractive optics, in combination with the use of advanced micromechanics and fast computing, that enables ZPAL to open up a new application space in lithography. This thesis addresses in detail all levels of the ZPAL system, from the micromechanics, to the …
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Imaging of Caenorhabditis Elegans with Near Infrared Spectrally Encoded Confocal Microscopy
… illumination in conjunction with refractive and diffractive optics to instantaneously image a confocal image line at a speed of up to 147 kHz with lateral and axial resolutions of 2m and 10m, respectively. Our imaging results from wild-type C. elegans and four mutant strains demonstrate the …
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Terahertz imaging arrays for room temperature operation summary of doctoral thesis /
… in order to shorten THz imaging time. Developed diffractive optics components, which have a sharp focusing performance and advantage of high selectivity in a frequency scale, let to improve the spatial resolution of imaging system up to 25 %. Also, the zone plate integration idea on the substrate …
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Diffractive gratings in high-precision interferometry for gravitational wave detection
… shown to occur due to lateral displacement of diffractive optics. These couple noise from interferometer alignment into the gravitational wave phase signal. For the end-mirror tilt of a 3 km Fabry-Perot arm cavity as used in gravitational wave detectors, this was found to set quite severe …
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Optical Printing of Multiscale Hydrogel Structures
… induced densification in Chapter 3, (ii) develop diffractive optics based on changes in refractive indices in Chapter 4, (iii) print diffractive optical elements in Chapter 5, and (iv) digitally print complex microfluidic devices and other 3D constructs in Chapter 6. Overall, this work open doors …
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Strain-tuning of periodic optical devices : tunable gratings and photonic crystals
… devices will be discussed: the fundamental diffractive grating element, and a photonic band gap microcavity waveguide. For the first part, we demonstrate high-resolution analog tunability in microscale diffractive optics. The design concept consists of a diffractive grating defined onto a …
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Distinguishing Homogeneous and Heterogeneous Origins of Nonexponential Dynamics Using Multiple Population Period Transient Spectroscopy
… mainly three challenges were addressed: first diffractive optics were used to generate passively phase stabilized pulses, second spherical aberration problem was solved by using meniscus lens and third a new balanced detection method was developed to isolate higher order resonant response. …
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Performance and Analysis of a Deployable Diffractive Optical Element for Small Satellite Missions
… lighter, and more deployable instrumentation, diffractive optical elements (DOEs) offer a compelling alternative to traditional optics. Their ability to focus light through engineered phase profiles rather than curved surfaces allows for large-aperture, flat optics that are far lighter and …
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Modeling and controlling topographical nonuniformity in thermoplastic micro- and nano-embossing
… manufacturing micro- and nanofluidic devices and diffractive optics. Meanwhile, the imprinting of sub-micrometer-thickness thermoplastic layers has emerged as a lithographic technique with exceptional resolution. Yet neither hot micro-embossing nor thermal nanoimprint lithography will be fully …
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Realization of a 3D gradient index medium in porous silicon
… multiplanar nanophotonic elements, and complex diffractive optics. This work paves a new path for designing novel subsurface optical elements with future applications in imaging and point spread function modification.
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Inverse techniques: problems in optics and gas sensing
… gas concentration measurements and designing diffractive optics (i.e. computer generated holograms), which on illumination will produce a desired light beam in the far field. The similarity between these problems is that they are both “inverse problems” and we discuss the use of inverse …
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Monolithic Integration Of Dual Optical Elements On High Power Semicond
… potential for monolithic integration of coupling optics on the wafer. We then show that differential quantum efficiency of 65%, the highest reported for a grating-coupled device, can be achieved by lowering the substrate reflectivity using a 200nm period tapered subwavelength grating that has a …
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Aspects of mirrors and suspensions for advanced gravitational wave detectors
… and fibres, test mass mirror coatings and also diffractive surfaces on test masses to evaluate their suitability for employment in future advanced gravitational wave detectors. Upgrade of LIGO to "Advanced LIGO" will aim to reduce thermal noise by implementing mirror suspension techniques …