Improving spatial resolution in non-linear optical diagnostics
Lead Research Organisation:
UNIVERSITY OF OXFORD
Department Name: Engineering Science
Abstract
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Organisations
Studentship Projects
| Project Reference | Relationship | Related To | Start | End | Student Name |
|---|---|---|---|---|---|
| EP/N509711/1 | 30/09/2016 | 29/09/2021 | |||
| 1798307 | Studentship | EP/N509711/1 | 30/09/2016 | 01/03/2021 | Priyav Shah |
| Description | As explained in my research proposal, the aim of my research is to increase the resolution of a laser-based temperature diagnostic called LITGS (Laser Induced Thermal Grating Spectroscopy). When two laser beams are crossed together, a fringe pattern is formed within the region where both beams overlap ('interaction region'). In the presence of a suitable gas (based on the wavelength of the laser beams used), a third beam, when be directed at this interaction region, will be scattered off this region to produce a signal beam. This signal is then analysed to determine the temperature of the gas. The spatial resolution of this technique is limited by the size of the interaction region. I had proposed overlapping four laser beams to create a 'Moiré fringe pattern' which would be smaller in size than the standard one created by two beams. During the initial stages of my research, I was able to experimentally prove that this was indeed the case, and preliminary results suggested a decrease in size of about 90%. During my PhD, I have also investigated another approach to increasing the spatial resolution of LITGS. This is by splitting up the signal beam into different parts, and mapping each part to where it originated within the interaction region. By doing this, we can essentially split up the interaction region into smaller sections, and measure the temperature within each section simultaneously. At the International Symposium on Combustion I presented results proving that the signal beam can indeed be split up and mapped back to parts of the interaction region. Since then I have successfully implemented this concept in a LITGS experiment. |
| Exploitation Route | I intend to build upon my findings by independently implementing both methods to common combustion problems in order to characterise each solution. Following this, my findings may be put to use in any application where a spatially resolved, non-intrusive temperature measurement is required - for example, within an optical engine. |
| Sectors | Aerospace Defence and Marine Energy Environment Pharmaceuticals and Medical Biotechnology Transport |