Based on Raman and hyper-Raman scattering experiments and on direct green light absorption measurements, excitations of a new type — charge transfer excitons — are found to exist in Ge-doped silica fibers, whose self-organization (orientation ordering of dipole moments) leads to positive feedback in response to a static electric field. An electric field of 10⁵ V/cm then results breaking the inversion symmetry of the initially centrally symmetric medium and allowing the second harmonic to be generated. Generation persists only at the medium preparation stage and self-switches off upon a transition to the stationary state.

PACS: 42.81.Qb, 61.43.Fs, 72.20.Jv (all) DOI: 10.1070/PU2001v044n01ABEH000867 URL: https://ufn.ru/en/articles/2001/1/b/ 000167145400002 Citation: Antonyuk B P, Antonyuk V B "Self-organization of excitations in Ge-doped silica fibers and its role in second harmonic generation" Phys. Usp. 44 53–70 (2001) BibTexBibNote ® (generic)BibNote ® (RIS)MedlineRefWorks Оригинал: Антонюк Б П, Антонюк В Б «Самоорганизация возбуждений в германосиликатных волоконных световодах и ее роль в генерации второй гармоники» УФН 171 61–78 (2001); DOI: 10.3367/UFNr.0171.200101b.0061