Please use this identifier to cite or link to this item:
|Document Type: ||Thesis or dissertation|
|Title: ||The fabrication of micro-tapered optical fibres for sensing applications|
|Authors: ||Mullaney, Kevin|
|Supervisors: ||Tatam, Ralph P.|
James, Stephen W.
|Issue Date: ||Nov-2016|
|Abstract: ||This thesis describes the processes used to manufacture optical fibre tapers and tapered
long period gratings (TLPGs) using a CO2 laser. A semi-automated system for
fabricating adiabatic and non-adiabatic tapers with repeatable physical dimensions has
been developed. The tapers had waist diameters which were reproducible to within
± 0.5 μm. This system has also been used to fabricate TLPGs with periods ranging from
378 μm to 650 μm.
Novel techniques to monitor the process of fabricating tapers were also explored. These
techniques included; monitoring the transmission of the fibre using a
spectrophotometer, using an in-line fibre Bragg grating (FBG) to measure the strain
experienced by the optical fibre and the use of a near infra-red (NIR) camera to aid fibre
alignment and laser power optimisation. The spectrophotometer allowed the optical
properties of the tapers to be tailored for specific applications and the FBG provided
strain data for process optimisation. The use of a NIR camera and an FBG as an in-line
strain sensor are a novel use of these devices in a fibre tapering process.
Tapers were also thin-film coated using sputtering techniques to form surface plasmon
resonance sensors and their refractive index sensitivity was measured. A novel protein
sensor based on gold nanoparticles deposited on a fibre taper is also reported, together
with a lossy mode resonance taper sensor.
The TLPGs which were fabricated, comprised of between 6 to 18 periods. The
refractive index sensitivity of a 6 period TPLG was measured and was 372 nm/ RI.
Their resonance bands had twice the bandwidth and exhibited a higher extinction,
compared to UV-written long period gratings of a similar number of periods.|
|Appears in Collections:||PhD and MSc by research theses (SATM)|
Items in CERES are protected by copyright, with all rights reserved, unless otherwise indicated.