Polarisation independent liquid crystal lenses and contact lenses using embossed reactive mesogens. Issue 3 (24th January 2020) - Jones, J. Cliff
Abstract: Liquid 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. Abstract : Polarisation independence for either diffractive or refractive switchable lenses is described, using birefringent lens structures that are index matched to a contacting liquid crystal. The production method and results for a diffractive Fresnel lens are described in detail and the prospects for using the method in refractive lenses such as adaptive contact lenses considered.