Polarisation dependent refractive device exhibiting independtly varying first and second indices of refraction and methods of manufacture thereof

A method of making a polarisation dependent refractive device, comprising exposing a photosensitive material exhibiting photo-induced birefringence to a polarized light beam spatially modulated in accordance with a predetermined pattern to form a birefringent element having a first refractive index to light polarised along a first direction, which first refractive index varies as a first function of position, and a second refractive index to light polarised along a second direction, which second refractive index is a second function of position, at least one of the second refractive index and the second function being different to the respective one of the first refractive index and the first function, and wherein the second function is an independent function of the first function.

A method of making a polarisation dependent refractive device, comprising forming a spatially varying ion concentration within a material exhibiting birefringence as a function of ion concentration to form a a birefringent element having a first refractive index to light polarised along a first direction, which first refractive index varies as a first function of position, and a second refractive index to light polarised along a second direction, which second refractive index is a second function of position, at least one of the second refractive index and the second function being different to the respective one of the first refractive index and the first function, and wherein the second function is an independent function of the first function.

A method of making a polarization dependent refractive device, comprising irradiating a cell of an aligned photosensitive liquid crystal monomer or polymer with radiation of spatially varying intensity, changing the liquid crystal alignment, and subsequently irradiating the cell with radiation of uniform intensity to form a a birefringent element having a first refractive index to light polarised along a first direction, which first refractive index varies as a first function of position, and a second refractive index to light polarised along a second direction, which second refractive index is a second function of position, at least one of the second refractive index and the second function being different to the respective one of the first refractive index and the first function, and wherein the second function is an independent function of the first function.