| EPSRC Reference: |
GR/J79720/01 |
| Title: |
ENHANCED ELECTROREFRACTIVE EFFECTS IN SHAPED QUANTUM WELLS FOR OPTICAL MODULATION |
| Principal Investigator: |
Allsopp, Dr D |
| Other Investigators: |
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| Department: |
Electronics |
| Organisation: |
University of York |
| Scheme: |
Standard Research (Pre-FEC) |
| Starts: |
01 October 1994 |
Ends: |
30 June 1998 |
Value (£): |
196,104
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| EPSRC Research Topic Classifications: |
| Optoelect. Devices & Circuits |
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Summary on Grant Application Form |
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a) to investigate enhanced electrorefraction in quaternary stepped alloy quantum wellsb) to investigate enhanced electrorefraction in GaAs/AlGaAs stepped alloy quantum wellsc) to investigate enhanced electrorefraction in GaAs/AlGaAs quantum wells shaped by delta-dopingd) to investigate experimentally and by extensive device simulation Mach-Zehnder interferometric light modulators that utilise enhanced electrorefraction in such shaped quantum wellsProgress:The possibility of enhancing the refractive index change with applied electric field, associated with the Quantum Confined Stark Effect, by optimally shaping semiconductor quantum wells was shown to be theoretically feasible, as part of a previous Research Council Grant (GR/G48695). This result has potential significance to a range of photonic devices (interferometric modulators, tunable optical filters etc) that rely on electrorefraction. The present work builds on this discovery. An algorithm that describes more completely excitonic mixing in the Greens function calculation has been developed. The new technique will allow the efficient computation of quantum well electroabsorption spectra over a wider energy range, to treat more accurately the long range contributions to the electrorefractive effect. This represents a significant extension to the theory and will result in greatly improved simulation of quantum well absorption spectra. A simple, direct method for measuring electrorefractive effects in quantum wells has been devised. The technique relies on detecting the interference between weakly absorbed light reflected from the front and rear facets of a sample in the form a slab waveguide. Preliminary experiments with 855 nm laser light in delta-doped GaAs/AlGaAs quantum wells samples are encouraging. A tunable diode laser for measurements in the 1550 nm wavelength has been purchased and installed.
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Key Findings |
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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 |
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This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
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Impacts |
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| 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 |
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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.york.ac.uk |