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Multiphoton absorption in direct gap solids
Author(s) -
Mitra S. S.,
Vaidyanathan A.
Publication year - 1981
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/jrs.1250100147
Subject(s) - semiconductor , attenuation coefficient , perturbation theory (quantum mechanics) , chemistry , two photon absorption , halide , perturbation (astronomy) , absorption (acoustics) , direct and indirect band gaps , photon , band gap , atomic physics , optics , quantum mechanics , physics , laser , inorganic chemistry
The two photon absorption coefficient for several alkali halides and zincblende type semiconductors has been calculated by models developed by Keldysh, Braunstein and Basov. It is shown that the Keldysh formula is closely related to Braunstein's for allowed‐allowed transitions, while Basov's formula correspond to Braunstein's formula for allowed‐forbidden transitions. A number of inprovements and corrections are pointed out. However, comparison with published experimental data show that even the best calculated values are at least an order of magnitude smaller. A more realistic model that combines the elements of second order perturbation theory and band structure calculations gives excellent agreement with experimental data on several direct gap semiconductors. The three photon absorption coefficient is treated by a third order perturbation method and compared to the results obtained by the Keldysh model.