EPSRC Reference: |
EP/H044922/1 |
Title: |
Magneto-optical Kerr effect with non-uniform optical polarisation |
Principal Investigator: |
Allwood, Professor DA |
Other Investigators: |
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Researcher Co-Investigators: |
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Project Partners: |
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Department: |
Materials Science and Engineering |
Organisation: |
University of Sheffield |
Scheme: |
Standard Research |
Starts: |
01 September 2010 |
Ends: |
30 November 2011 |
Value (£): |
149,064
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EPSRC Research Topic Classifications: |
Materials Characterisation |
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EPSRC Industrial Sector Classifications: |
No relevance to Underpinning Sectors |
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Related Grants: |
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Panel History: |
Panel Date | Panel Name | Outcome |
25 Feb 2010
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Physical Sciences Panel - Materials
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Announced
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Summary on Grant Application Form |
The magneto-optical Kerr effect (MOKE) is widely used to characterise the magnetic behaviour or state of materials. Uniform beam polarisations are invariably used in MOKE measurements, whether as a parallel beam for thin film measurements or a focussed beam for measurements of small magnetic structures. Observing MOKE from in-plane magnetisation requires an oblique angle of incidence, with higher signals generally obtained with larger angles of incidence. This leads to a compromise being reached between spatial resolution and signal. Tightly focussed light beams are not purely transverse and can have a component of longitudinal electric field in the vicinity of the focus. Radially polarised light beams can significantly increase this effect and have a much reduced focal spot size for the longitudinal field component. We propose to use the longitudinal electric field associated with tightly focussed radially-polarised laser beams to perform normal-incidence MOKE measurements on materials with in-plane magnetisation. This will allow exquisite spatial resolution of magnetic thin films and nanostructures, plus the unprecedented ability to depth-resolve magnetisation. Optimising this will require a new framework to relate the relevant physics of MOKE with non-uniform optical polarisation. The three advantages of radial-polarisation MOKE (R-MOKE) are:1. An order of magnitude increase in the longitudinal component of electric field (which couples to the in-plane magnetisation to generate a Kerr signal)2. A reduction of the transverse spot size affording higher spatial resolution3. The unprecedented ability to depth-resolve magnetisation in MOKE measurements.
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Key Findings |
This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
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Potential use in non-academic contexts |
This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
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Impacts |
Description |
This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk |
Summary |
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Date Materialised |
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Sectors submitted by the Researcher |
This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
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Project URL: |
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Further Information: |
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Organisation Website: |
http://www.shef.ac.uk |