9 resultados para Optics|Biophysics

em Aston University Research Archive


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This thesis is a sociological study of the ophthalmic optical profession in Britain. It includes a survey of the development of ophthalmic optics as an occupation and three questionnaire, surveys, one each of first and final year ophthalmic optics students, and one of practising opticians. The developmental survey showed that four themes have been important in the occupation's process of professionalisation - the actions of the opticians' leaders, the gradual unification of the bodies, representing segments of the profession, the struggle with medicine and the involvement of ophthalmic opticians in state-organised optical welfare schemes. The student surveys showed that the profession is now recruiting largely from middle class, state educated groups, and increasingly from women, who hold significantly different attitudes to income, independence and career commitment. In general, both first and final year students considered service to be rather more important than furthering knowledge. Practising opticians have been recruited increasingly, from middle class backgrounds, mostly from state selective secondary schools, but with a large minority from non-state schools. The self-recruitment rate of the profession (18.9%) is very similar to that for British medical students. Significant differences in concepts of professionalism were found among ophthalmic opticians of different ages, sexes and types of practice but few among those in different areas of practice. In general, ophthalmic opticians seemed to stress service more·than furthering knowledge. It is suggested that the leaders of the profession have 'negotiated' considerable autonomy for its members and that the possibilities for commercialism within the ophthalmic optician's professional role are intrinsically no greater than those in more 'established' professions.

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Optical fiber materials exhibit a nonlinear response to strong electric fields, such as those of optical signals confined within the small fiber core. Fiber nonlinearity is an essential component in the design of the next generation of advanced optical communication systems, but its use is often avoided by engineers because of its intractability. The application of nonlinear technologies in fiber optics offers new opportunities for the design of photonic systems and devices. In this chapter, we make an overview of recent progress in mathematical theory and practical applications of temporal dissipative solitons and self-similar nonlinear structures in optical fiber systems. The design of all-optical high-speed signal processing devices, based on nonlinear dissipative structures, is discussed.

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We present recent results on femtosecond microfabrication of key components for integrated optics such as highly curved low-loss waveguides in glasses, depressed cladding waveguides in crystals. Details of microfabrication and characterisation are discussed.

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The diagnosis of ocular disease is increasingly important in optometric practice and there is a need for cost effective point of care assays to assist in that. Although tears are a potentially valuable source of diagnostic information difficulties associated with sample collection and limited sample size together with sample storage and transport have proved major limitations. Progressive developments in electronics and fibre optics together with innovation in sensing technology mean that the construction of inexpensive point of care fibre optic sensing devices is now possible. Tear electrolytes are an obvious family of target analytes, not least to complement the availability of devices that make the routine measurement of tear osmolarity possible in the clinic. In this paper we describe the design, fabrication and calibration of a fibre-optic based electrolyte sensor for the quantification of potassium in tears using the ex vivo contact lens as the sample source. The technology is generic and the same principles can be used in the development of calcium and magnesium sensors. An important objective of this sensor technology development is to provide information at the point of routine optometric examination, which would provide supportive evidence of tear abnormality.

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Optical fiber materials exhibit a nonlinear response to strong electric fields, such as those of optical signals confined within the small fiber core. Fiber nonlinearity is an essential component in the design of the next generation of advanced optical communication systems, but its use is often avoided by engineers because of its intractability. The application of nonlinear technologies in fiber optics offers new opportunities for the design of photonic systems and devices. In this chapter, we make an overview of recent progress in mathematical theory and practical applications of temporal dissipative solitons and self-similar nonlinear structures in optical fiber systems. The design of all-optical high-speed signal processing devices, based on nonlinear dissipative structures, is discussed.

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We present recent results on femtosecond microfabrication of key components for integrated optics such as highly curved low-loss waveguides in glasses, depressed cladding waveguides in crystals. Details of microfabrication and characterisation are discussed. © 2009 Optical Society of America.