Broadband Terahertz Spectroscopy of Phonon-Polariton Dispersion in Ferroelectrics
Electromagnetic waves at frequencies below the X-ray region strongly couple to the optical vibrational modes in a solid. These coupled excitations have been called phonon polaritons. The relationship of the polariton frequency versus the polariton wavevector shows a remarkable dispersion, especially...
| Published in: | Photonics |
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| Main Author: | |
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2018-12-01
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| Subjects: | |
| Online Access: | https://www.mdpi.com/2304-6732/5/4/55 |
| Summary: | Electromagnetic waves at frequencies below the X-ray region strongly couple to the optical vibrational modes in a solid. These coupled excitations have been called phonon polaritons. The relationship of the polariton frequency versus the polariton wavevector shows a remarkable dispersion, especially in the vicinity of the transverse and longitudinal optical mode frequencies. The significant frequency dependence enables valuable applications such as a tunable terahertz radiation source. The polariton dispersion relations of technologically important dielectric and ferroelectric crystals were reviewed in the broad terahertz range using terahertz time-domain spectroscopy, far-infrared spectroscopy, and Raman scattering spectroscopy. |
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| ISSN: | 2304-6732 |