Abstract
We perform degenerate four-wave-mixing (FWM) studies of GaN excitons especially for an understanding of the strain-fields in the heteroepitaxial films. The shifts of exciton energies and their beating oscillation variations highlight the biaxial strain, allowing for a precise determination of the strain parameters. The uniaxial strain field can be characterized by the polarization dependence of FWM, which shows distinct polarizations and energy variations depending on the sample and its position. The minimum changes of the polarized FWM intensity and exchange energy splittings correspond to a uniaxial strain of 5.0 × 10-5, which currently gives a lower resolution limit of this technique and is comparable with that of conventional X-ray diffraction. In the time-evolutions, we investigate the strain effects on the phase of the quantum beats (QBs), giving insight into the excitons interactions. By using time-resolved FWM, difference between two-types of exciton transitions is identified. In addition, coherent manipulations of QBs are successfully realized in the FWM with a Michelson interferometer..
Original language | English |
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Title of host publication | Ultrafast Phenomena in Semiconductors and Nanostructure Materials XII |
DOIs | |
Publication status | Published - 2008 |
Event | Ultrafast Phenomena in Semiconductors and Nanostructure Materials XII - San Jose, CA, United States Duration: 2008 Jan 20 → 2008 Jan 23 |
Publication series
Name | Proceedings of SPIE - The International Society for Optical Engineering |
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Volume | 6892 |
ISSN (Print) | 0277-786X |
Conference
Conference | Ultrafast Phenomena in Semiconductors and Nanostructure Materials XII |
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Country/Territory | United States |
City | San Jose, CA |
Period | 08/1/20 → 08/1/23 |
Keywords
- Coherent control
- Exciton
- Four-wave-mixing
- GaN
- Quantum beat
- Strain