Measurement and analysis of reversible transformations of vortex-free and singular light fields produced by PDLC cells

• Published in: Semiconductor Physics Quantum Electronics & Optoelectronics
• Date: 2009
• Main Authors: Ponevchinsky, V.V., Vasil’ev, V.I., Soskin, M.S.
• Format: Article
• Language: English
• Published: Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України 2009
• Online Access: https://nasplib.isofts.kiev.ua/handle/123456789/118868
• Journal Title: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Cite this: Measurement and analysis of reversible transformations
 of vortex-free and singular light fields produced by PDLC cells / V.V. Ponevchinsky, V.I. Vasil’ev, M.S. Soskin // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2009. — Т. 12, № 3. — С. 234-239. — Бібліогр.: 16 назв. — англ.

In this work, we have firstly realized and investigated reversible
 transformations of vortex-free and singular optical complex landscapes appearing in a
 He-Ne laser beam transmitted through a PDLC cell, which is controlled by an applied
 DC voltage. Biaxes of all micro size LC domains are oriented approximately along the
 applied electric field, and vortex-free complex landscape exists at 200 V. At 160 V,
 biaxes orientation spreads, and the first ‘embryo’ of vortices in the form of a smooth
 phase step appears. The first vortex pair nucleates at 140 V. Multitude of vortex pairs is
 realized when electric field is switched off. Reversed evolution is realized when the
 applied DC voltage grows from zero value to 200 V. It was shown that the observed
 topological evolution is fully defined by changes in structure and localization of real and
 imaginary zero-intensity lines for output complex light field. The developed technique of
 parametric dynamics can be applied successfully to realize and investigate various types
 of controlled optical elements including media with nanoadditions.