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Spectral features of the Borrmann effect in 1D photonic crystals in the Laue geometryстатья
Информация о цитировании статьи получена из
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Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 27 января 2018 г.
- Авторы: Novikov V.B., Mantsyzov B.I., Murzina T.V.
- Журнал: Proceedings of SPIE - The International Society for Optical Engineering
- Том: 10227
- Номер: May 16
- Год издания: 2017
- Издательство: SPIE, the International Society for Optical Engineering
- Местоположение издательства: Bellingham, WA, United States
- Первая страница: 301
- Последняя страница: 311
- DOI: 10.1117/12.2264602
- Аннотация: The Borrmann effect is the fundamental effect in X-ray physics. It is a strong increase of the transmission of a perfect crystal when the X-rays satisfy the Bragg diffraction condition, originating from X-rays localization between the atomic planes in that case. In other words, the Borrmann effect manifests itself by smaller field losses as the Bragg diffraction law is attained. Following the trend of the transfer of the X-ray phenomena into the optical spectral range, in this work we experimentally observed and studied the optical analog of the Borrmann effect for the case of one-dimensional photonic crystals (PhCs). The studies are performed in the Laue diffraction scheme when no photonic band gaps appear and the light does not experience diffraction-induced light attenuation. We studied the samples of PhCs based on porous fused silica. Samples’ manufacturing consists of two stages. First, porous silicon PhCs are fabricated by electrochemical etching of p-doped Si (100) wafer. The PhCs consist of alternating layers of two types, of high and low porosity, characterized by different refractive indexes. The second stage consists in annealing of the crystals in a muffle at 750o C. Depending on the oxidation time, we obtained the PhCs that are partially or fully annealed. The PhCs produced by both techniques have periodical modulation of refractive indexes and losses. Optical losses in the two types of PhCs are different; in partially annealed PhCs (PhC-I) high refractive index layers absorb light due to the presence of residual silicon, while in fully annealed structures (PhC-II) the losses are determined by light scattering in layers with high porosity (low refractive index layers). PhCs have several hundreds of layers that allow study the effect in the Laue scheme of diffraction. Optical experimental setup is based on a CW laser operating at the wavelength of 720-890 nm, its linearly polarized beam is focused by a lens on the PhC input edge of the into a spot of 130 nm. The silicon photodiode with a large detection region is placed close to the PhC output edge, so the total transmission is measured, including the beams of all diffraction maxima. We studied the transmission of the two types of PhCs as a function of the angle of incidence of the radiation. We observe that the transmission of the PhC-I samples demonstrates sharp peaks, corresponding to the Bragg angles of diffraction. The appearance of these peaks manifests of the Borrmann effect due to the predominant localization of the optical field in the PhC layers with low absorption. At the same time, the PhC-II structures demonstrate nearly monotonic decreasing of transmission as a function of the angle of incidence. So the effect is different for the structures with light losses in high or low refractive index layers. Spectral dependence of the effect shows a number of peculiarities: alternating appearance and disappearance of total transmission maxima and a strong angular narrowing of maxima for definite wavelengths. Interrelation of the observed effects with degeneracies of the PhC band structure is confirmed by theoretical calculations.
- Добавил в систему: Манцызов Борис Иванович