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Photonics is revolutionising the way we live in a similar way to what electronics historically did. The main aim of this PhD project was to investigate and develop fabrication techniques leading to the realisation of mid-infrared photonic components based entirely on chalcogenide glass compositions which were prepared in-house, here at the University of Nottingham, Nottingham, UK. Chalcogenide glasses are based on the chalcogen elements of Group XVI of the Periodic Table and were chosen over conventional silica glass in the work described in this thesis for their significant advantages such as: a wide transmission window, for wavelengths of light from O .5 ~tm up to 25~tm depending on the glass composition, low phonon energies, high non-linearities and high refractive indices. The chalcogenide glass systems of As-Se, Ge-As-Se and Te-As-Se were synthesised and a new quenching technique was developed to prevent ampoule failures. In addition, the distillation of Te-As-Se system was optimised via the use of temperature monitoring. Two simulations were developed using commercial software; the first led to a large mode area, endlessly single mode microstructured optical fibre design and the second verified the photonic band gaps of a photonic band gap fibre from the literature. In particular, a methodology leading to the automation of chalcogenide glass cane drawing, a hot-collapse rig for investigating hot-collapsing of a tube onto a rod and a stacking mechanism for stacking chalcogenide glass canes have all been established as part of fabrication route that has been d~veloped towards the realisation of a chalcogenide glass all-solid core microstructured optical fibre (MOF) comprising 37 core/clad canes based on the design parameters simulated. Furthermore, a robust method for obtaining for the first time multimode optical couplers based on core-clad chalcogenide glass fibre using the method of fibre sidepolishing has been demonstrated experimentally. A key feature is a novel and reproducible procedure developed for obtaining controlled side (D) polishing of chalcogenide glass fibre using an innovative polishing apparatus. These achievements are particularly noteworthy because chalcogenide glass fibre is "more toxic (requiring the use of fume extractors), requires inert atmosphere to prevent oxidation and complicated preparation methods, is difficult to handle and, due to the higher refractive indices, exhibits a higher degree of reflection at glass-air (~20%) interfaces than conventional silica glass fibre. Over the last few years, infrared rnicroscopy (IR) has gained interest and has been used to study cells and tissues for cancer diagnosis. The fabrication of IR-transmitting chalcogenide glass optical fibre tips has been investigated and tips exhibiting reproducible and controlled taper geometries have been demonstrated experimentally. f --- Additionally, methods for metal-coating the tips in a thermal evaporation chamber and cleaving the tips using a focused ion beam (FIB) have been successfully developed. Small diameter tips have been used as an IR probe in scanning near-field infrared microscopy (SNIM) and larger diameter tips for transflection spectroscopy in an attempt to obtain optical and topographical cell tissue data for cell IR fingerprint recognition of Chinese Hamster Ovary cells using synchrotron radiation by employing B22 Beamline of the Diamond Light Source, Oxford, UK. IR spectra was successfully collected and showed good indication of the amide I and amide II bands related with cell DNA. |
