標題: | Lens-less bending and concentration of light by volume hologram |
作者: | Hsieh, Mei-Li Peng, Cheng-Te Chen, Hong-Yu Lin, Shawn-Yu 光電工程學系 Department of Photonics |
關鍵字: | Holographic optical elements;Volume gratings;Diffractive optics |
公開日期: | 1-十二月-2015 |
摘要: | In this paper, a new approach is proposed to realize a lens-less and 90 degrees light-bending by a volume-holographic element, consisting of 3D sub-wavelength index-gratings throughout the sample. In this approach, a top incident plane-wave is diffracted by 90 degrees and guided into a planar volume hologram. Conversely, a side-incident light may be guided and diffracted out of the top sample surface. The diffraction-efficiency eta of light was studied in real-time during light-exposure and also in the dark after exposure to observe "dark-enhancement". It is shown that 90 degrees light-bending at normal incidence can be achieved with a high efficiency, eta similar to 70%, and a small angular-tolerance, Delta theta=0.02 degrees. It is further shown, as a proof-of-concept, that a 5 degrees cylindrical-wave top-incident beam may be used to improve angular tolerance to Delta theta=5 degrees, but with a reduced efficiency of eta similar to 0.80%. Crown Copyright (C) 2015 Published by Elsevier B.V. All rights reserved. |
URI: | http://dx.doi.org/10.1016/j.optcom.2015.07.046 http://hdl.handle.net/11536/128206 |
ISSN: | 0030-4018 |
DOI: | 10.1016/j.optcom.2015.07.046 |
期刊: | OPTICS COMMUNICATIONS |
Volume: | 356 |
起始頁: | 12 |
結束頁: | 16 |
顯示於類別: | 期刊論文 |