Polarisation independent liquid crystal lenses and contact lenses using embossed reactive mesogens

J Cliff Jones,Joe Sargent,James Bailey,Markus Wahle,Tom Moorhouse,Benjamin Snow

doi:10.1002/jsid.874

J Cliff Jones, Joe Sargent + Show 4 more

Open Access

https://doi.org/10.1002/jsid.874

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Abstract

AbstractLiquid crystal lenses have promise in optical systems owing to their tunability combined with low electrical power, cost, and weight. A good example of such a system is switchable contact lenses for the correction of age‐related presbyopia. Sufficiently large phase modulation can be done using nematic liquid crystals in a meniscus lens configuration. However, the birefringent materials are inherently polarisation dependent, usually requiring orthogonal polarisations to be focussed separately. A novel method is presented for producing polarisation independent lenses based on reactive mesogens. Results are presented for a 2‐level and 3‐level diffractive Fresnel lenses, and the promise of the technique for use in refractive lenses such as contact lenses is discussed.

Highlights

The objective of the present work is to design an arrangement for a conventional nematic liquid crystal that could produce polarisation independent operation for either multi-level diffractive or refractive optical structures, producing high efficiency lenses operating at lower voltages
The lenses produced show both good topography and coaxial alignment. The latter is apparent from the uniform retardance colour when viewed at 45 to crossed polarisers (Figure 6A,C) and the excellent dark state when parallel to the crossed polarisers (Figure 6B, D), confirming that the embossing process produces structures with very small or zero offset
The empty, assembled cell (Figure 6E), where both substrates are rotated by 90 with respect to each other, shows a uniform bright state between crossed polarisers and independent of the orientation to the polarisers. This indicates that the good alignment of the reactive mesogen (RM) was transferred to the index-matched liquid crystal in the twisted nematic (TN) configuration

Summary

Objectives

The objective of the present work is to design an arrangement for a conventional nematic liquid crystal that could produce polarisation independent operation for either multi-level diffractive or refractive optical structures, producing high efficiency lenses operating at lower voltages

Methods

Results

Conclusion