This literature analysis examines terahertz (THz) imaging as a non-invasive tool for the imaging of friction ridge detail from the first painted layer (imprimatura) in multilayered painted works of art. The paintings of interest are those created utilizing techniques developed during the Renaissance and still in use today. The goal of analysis serves to answer two questions. First, can THz radiation penetrate paint layers covering the imprimatura to reveal friction ridge information? Secondly, can the this technology recover friction ridge detail such that the fine details are sufficiently resolved to provide images suitable for comparison and identification purposes. If a comparison standard exists, recovered friction ridge detail from this layer can be used to establish linkages to an artist or between works of art. Further, it can be added to other scientific methods currently employed to assist with the authentication efforts of unattributed paintings. Flanked by the microwave and far-infrared edges, THz straddles the electronic and optic perspectives of the electromagnetic spectrum. As a consequence, this range is imparted with unique and useful properties. Able to penetrate and image through many opaque materials, its non-ionizing radiation is an ideal non-destructive technique that provides visual information from a painting’s sub-strata. Imaging is possible where refractive index differences exist between different paint layers. Though it is impossible, at present, to determine when a fingerprint was deposited, one can infer approximately when a print was created if it is recovered from the imprimatura layer of a painting, and can be subsequently attributed to a known source. Fingerprints are unique, a person is only able to deposit prints while their physical body is intact and thus, in some cases, the multiple layer process some artists use in their work may be used to the examiner’s advantage. Impressions of friction ridge detail have been recorded on receiving surfaces from human hands throughout time (and have also been discovered in works of art). Yet, the potential to associate those recorded impressions to a specific individual was only realized just over one hundred years ago. Much like the use of friction ridge skin, the relatively recently discovered THz range is now better understood; its tremendous potential unlocked by growing research and technology designed to exploit its unique properties.

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Orientador: Jose Alexandre Diniz / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-11T06:36:37Z (GMT). No. of bitstreams: 1 Melo_ArlineMaria_D.pdf: 17701586 bytes, checksum: b5160ad894463745fdeea0dae1f71065 (MD5) Previous issue date: 2007 / Resumo: Este trabalho apresenta importantes informações sobre tecnologia THz, atualmente considerada um desafio tecnológico e estado da arte em diversas áreas de desenvolvimento. Com o objetivo de formar um sistema imageador THz, ainda indisponível comercialmente, foram dispensados esforços em diferentes frentes. Câmeras para o infravermelho médio (8 ¿ 14 µm) foram adquiridas, caracterizadas e testadas, com resultados relevantes e inéditos em Física Solar, aplicação considerada para este trabalho. Filtros de malha ressonante para diversas bandas na região THz (centrados em 0,4, 0,67, 0,85, 2, 4 e 8,5 THz) foram projetados, fabricados e testados exibindo excepcional resposta. E finalmente um primeiro protótipo imageador foi montado acoplando os filtros de malha ressonante a câmera IV sem sua óptica original de germânio. As primeiras imagens THz de uma resistência aquecida é apresentada, provando a funcionalidade do conceito original. Os desenvolvimentos e estudos aqui apresentados estarão contribuindo para dois experimentos espaciais recentemente propostos, DESIR ( Detection of Solar eruptive Infrared Radiation) e SIRA (Submillimeter-wave to InfraRed solar Activity emissions), prevendo a utilização de sistemas THz em observações de transientes em plasmas ativos solares em diferentes freqüências, a partir do solo e no espaço / Abstract: This work presents important information on THz technology, currently considered a technological challenge and state of the art in different areas of development. To form a THz imaging system, still unavailable commercially, efforts in different fronts had been excused. Cameras for medium IR (8 - 14 µm) had been acquired, characterized and tested, with excellent and unknown results in Solar Physics, application considered for this work. Filters of resonant metal mesh for diverse bands in the THz region (centered in 0,4, 0,67, 0,85, 2, 4 and 8,5 THz) had been projected, manufactured and tested showing excellent results. Finally a first imaging system was mounted connecting the filters of resonant mesh to the IR camera without its original optics of germanium. The first THz images of a warm resistance are presented, proving the functionality of the original concept. The developments and studies presented here will contribute for two space experiments recently considered, DESIR ( Solar Detection of eruptive Infrared Radiation) and SIRA ( Submillimeter-wave you the solar InfraRed Activity emissions), requiring the use of THz systems for observations of transient in solar active plasmas in different frequencies, from the ground and in the space / Doutorado / Eletrônica, Microeletrônica e Optoeletrônica / Doutor em Engenharia Elétrica

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