Abstract
This thesis presents the integration of aerogel and fibre optic technologies. We have developed several methods for fabricating aerogels that can transmit laser beams with low distortion and have a low attenuation of 0.07 dB/cm at 1310 nm. The refractive index of our aerogel can be varied between 1.025–1.05 by varying the density between 0.1–0.22 g/cm3 . These aerogels can be slightly birefringent, and we demonstrate that a 1 cm thick aerogel could be used similarly to a Babinet compensator. New methods have allowed us to controllably alter the optical properties of aerogel by the inclusion of dopants. Plasmonic aerogel created using our technique offers the unique opportunity to study unclustered and well-dispersed gold nanoparticles in an air-like environment, with applications in spectroscopic sensing and nonlinear optics. The simple and cheap method we have developed for doping aerogel with lanthanide ions could have a significant impact in the fabrication of glasses for laser materials.We have created techniques for making aerogel in or around fibre optics so that we can use it to control the flow of light. Our method of filling a hollow core fibre has enabled transmission through an unprecedented length of aerogel. The aerogel-filled fibre operates in a single mode at 1550 nm, with attenuation of 0.2 dB/cm. Also, we have encapsulated a range of different sized tapered fibres in aerogel with low attenuation. Tapered optical fibres are sensitive to their immediate environment because the optical field propagates right at the boundary between glass and air. Our lowest attenuation, 0.03 dB/mm at 1310 nm for a 750 nm diameter taper, represents an order of magnitude improvement over using other materials as the encapsulant. We have demonstrated the uses of tapered fibres packaged in aerogel as fused couplers, evanescent gas sensors, and in nonlinear light sources.
| Date of Award | 1 Nov 2010 |
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| Original language | English |
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| Supervisor | Tim Birks (Supervisor) |