Efficiency improvements in a dichroic dye-doped liquid crystal Fresnel lens

Ethan I.L. Jull*, Markus Wahle, Peter J.M. Wyatt, Colin Ellis, Stephen J. Cowling, John W. Goodby, Kiyoaki Usami, Helen F. Gleeson

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


A dichroic dye-doped liquid crystal Fresnel lens was fabricated and investigated to observe the combination of phase and amplitude modulation based focusing. An anthraquinone dichroic dye was doped into a liquid crystal host, which when in the Fresnel lens configuration, generates a Fresnel zone plate with alternating “transparent” and “opaque” zones. The zones were induced by using photo-alignment of a light-sensitive alignment layer to generate the alternating pattern. The voltage dependency of efficiency for the dye-doped and pure liquid crystal Fresnel devices were investigated. Incorporation of dyes into the device yielded a significant 4% improvement in relative efficiency in the lens, giving a maximum of 37% achieved in the device, much closer to the theoretical 41% limit when compared with the non-dye-doped device. The input polarization dependence of efficiency was also investigated, showing very small fluctuations (±1.5%), allowing further insight into the effect of fabrication method on these liquid crystal Fresnel devices.

Original languageEnglish
Pages (from-to)26799-26806
Number of pages8
JournalOptics Express
Issue number19
Publication statusPublished - 16 Sept 2019

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