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Kramers‐Kronig analysis of exciton spectra in case of spatial resonance dispersion
Author(s) -
Skettrup T.
Publication year - 1970
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.19700420238
Subject(s) - kramers–kronig relations , resonance (particle physics) , exciton , dispersion (optics) , polariton , reflection (computer programming) , spectral line , dielectric , dispersion relation , spatial dispersion , oscillator strength , optics , atomic physics , physics , chemistry , molecular physics , condensed matter physics , refractive index , quantum mechanics , computer science , programming language
The reflection spectrum of excitons exhibiting spatial resonance dispersion yields in a Kramers‐Kronig analysis values for the optical constants that deviate from the ones determined directly by transmission measurements. This is due to the extra polariton mode present in case of spatial resonance dispersion. In spite of this discrepancy, these values permit to derive sufficiently accurate the resonance frequencies, oscillator strengths, and background dielectric constants. The damping constant obtained in this way contains a mass‐dependent term in addition to the true damping of the excitons. We derive a necessary condition for the observation of spatial dispersion effects. An estimate for the exciton masses of some II–VI compounds is obtained from their low temperature reflection spectra.