Quantitative spectral data acquisition and analysis with modular smartphone assemblies

Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2014.Cataloged from PDF version of thesis.Includes bibliographical references (page 37).A low-cost cell phone spectrometer using the image sensor in the cell phone camera is developed and analyzed. The spectrometer design is optimized for sensitivity and spectral resolution. Calibration techniques are developed to enable robust data collection across different phone models with minimal equipment. Novel algorithms for robust calibration with minimal equipment are described and implemented. The spectrometer is then characterized for use in colorimetric systems. Finally, the cell phone spectrometer is used in a forensic application for dating blood spots based on time-dependent oxidation-induced spectral changes.by Michael Robert Harradon.M. Eng

Tailoring photonic metamaterial resonances for thermal radiation

Abstract Selective solar absorbers generally have limited effectiveness in unconcentrated sunlight, because of reradiation losses over a broad range of wavelengths and angles. However, metamaterials offer the potential to limit radiation exchange to a proscribed range of angles and wavelengths, which has the potential to dramatically boost performance. After globally optimizing one particular class of such designs, we find thermal transfer efficiencies of 78% at temperatures over 1,000&#176;C, with overall system energy conversion efficiencies of 37%, exceeding the Shockley-Quiesser efficiency limit of 31% for photovoltaic conversion under unconcentrated sunlight. This represents a 250% increase in efficiency and 94% decrease in selective emitter area compared to a standard, angular-insensitive selective absorber. PACS: 42.70.Qs; 81.05.Xj; 78.67.Pt; 42.79.Ek</p

Tailoring photonic metamaterial resonances for thermal radiation

Selective solar absorbers generally have limited effectiveness in unconcentrated sunlight, because of reradiation losses over a broad range of wavelengths and angles. However, metamaterials offer the potential to limit radiation exchange to a proscribed range of angles and wavelengths, which has the potential to dramatically boost performance. After globally optimizing one particular class of such designs, we find thermal transfer efficiencies of 78% at temperatures over 1,000&#176;C, with overall system energy conversion efficiencies of 37%, exceeding the Shockley-Quiesser efficiency limit of 31% for photovoltaic conversion under unconcentrated sunlight. This represents a 250% increase in efficiency and 94% decrease in selective emitter area compared to a standard, angular-insensitive selective absorber.National Science Foundation (U.S.) (MRSEC Program award number DMR-0819762)United States. Dept. of Energy (MIT S3TEC Research Frontier Center Grant No. DESC0001299)Massachusetts Institute of Technology. Institute for Soldier Nanotechnologies (Grant No. W911NF-07-D-0004)Massachusetts Institute of Technology. Institute for Soldier Nanotechnologies ((ISN-ARO) Grant No. Contract no. DAAD-19-02-D0002