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We derive the expression for the three-dimensional incoherent optical transfer function when third-order spherical aberration is present. The normalized version of the transfer function is numerically calculated for various amounts of spherical aberration. We find the effects of the aberration to be highly dependent on the spatial frequency in the longitudinal direction. We also calculate a structure content parameter, as a quality criterion, from the normalized transfer function. Remarkably, the structure content parameter dependence on spherical aberration is well-fit by a simple Cauchy curve for aberrations out to two waves at the margin.

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Carbon nanotubes are intriguing materials and extensively studied for both their fundamental properties and extraordinary performance in various applications during the last 20 years. They are extremely small in diameter, light in weight, sensitive to the environment, strong, and chemically stable. They can be either metallic or semiconducting depending on their species. The semiconducting species can absorb and emit light in a wide range of wavelengths. These outstanding properties of carbon nanotubes promise abundant applications that may be revolutionary. The opto-electronic behaviour of a single-walled carbon nanotube (SWCNT) is extremely sensitive to its physical structure and ambient environment. Structural defects and surrounding environment are extrinsic influential factors that often obscure the understanding of the intrinsic behaviour. Progress on SWCNT synthesis has been made continuously but not until the last 10 years, have single SWCNTs been isolated individually and from substrates so that their fluorescence can be detected. The fundamental science of an optically generated exciton (an electron-hole pair) in an ideal semiconducting SWCNT is not fully understood despite many studies of exciton behaviour using various optical approaches. The major challenge is controlling SWCNT sample qualities. SWCNT's fundamental properties, such as the absorption cross section, quantum efficiency, radiative and nonradiative lifetimes, remain under debate. Knowing the intrinsic SWCNT properties is essential to understand exciton transport and relaxation mechanisms. To minimize the extrinsic effects, we have selected high-quality unprocessed SWCNTs for investigation. Collaboration with Dr. P. Finnie and Dr. J. Lefebvre at National Research Council Canada, allow us to access pristine SWCNTs individually. Since the emission from a single SWCNT is low, it requires unconventional methods to measure the PL dynamics. Suggested by the results, exciton transport in a semiconducting SWCNT is diffusional at room temperature, with high diffusivity (130 -350 cm^2/s) and long diffusion length (1 - 5 µm). At lower temperatures, we observed a more efficient exciton-exciton interaction that suggests the contribution from hot excitons or a longer existence of delocalized excitons. Highly efficient exciton-exciton annihilation and long coherence time in a SWCNT are promising for making a single-photon source at near-infrared wavelength range and developing quantum computers. / Thesis (Ph.D, Physics, Engineering Physics and Astronomy) -- Queen's University, 2013-12-06 09:52:51.136

Darbo esmė giliau pažvelgti į brūkšninių kodų rūšis, panaudojimo galimybes ir išsiaiškinti jų privalumus bei trūkumus. Darbo tikslas išnagrinėti QR brūkšninio kodo sandarą, kiekvienos sudedamos dalies svarbą ir savybes. Taip pat sukurti programinę įrangą QR kodo lokalizavimui vaize ir palyginti su praktikoje naudojamais produktais. / This paper investigates different barcodes, use cases, advantages and disadvantages. Aim of this paper is to analyse stucture and characteristics of QR code, develop software to locate QR code in picture, compare results with other software.

This thesis describes and evaluates two new interferometric distance measurement methods based upon the well known method of Frequency Scanning Interferometry (FSI). These new methods are known as Dynamic FSI and Cascaded FSI. Dynamic FSI addresses the two problems, commonly seen in previous FSI implementa- tions, of not being able to measure a moving target and having a slow measurement rate. This method measures stationary and moving targets equally well, and can determine the distance to the target at all times during the measurement, in contrast to previous methods, which obtain only a single measured length from a measurement process which can take up to a second to make. Cascaded FSI was developed with the aim of increasing the accuracy and precision of FSI. This method allows for measurements with precision equal to that of displacement interferometry, and also provides a way of measuring length relative to the frequencies of atomic absorption lines, which are inherently more stable length references than a physical length artefact.