Abstract: An active random refraction device includes a random structure having the same refractive index characteristics regardless of polarization direction of light, a liquid crystal polymer on the random structure with refractive index characteristics changing according to polarization direction of the light, a polarization switching device, and a refractive surface with an inclination angle randomly distributed along the horizontal direction perpendicular to the incident direction of the light. The active random refraction device can be switched between a transmission mode and a refractive mode according to the polarization of the light.

Abstract: Disclosed are a holographic writing method and apparatus capable of re-writing (updating) holographic information and quickly writing the holographic information with high efficiency. In an embodiment, a holographic writing method for writing holographic information by emitting a beam at a holographic recording medium containing a photo-responsable polymer material having photoisomerization characteristics that change a molecular structure thereof by absorbing light energy, writes the holographic information by using a writing wavelength different from a maximum absorption wavelength in a light absorption spectrum of photoisomer molecule structures of the holographic recording medium. The maximum absorption wavelength is a wavelength at which light absorption rate is maximum in the light absorption spectrum.

Abstract: An active random refraction device includes a random structure having the same refractive index characteristics regardless of polarization direction of light, a liquid crystal polymer on the random structure with refractive index characteristics changing according to polarization direction of the light, a polarization switching device, and a refractive surface with an inclination angle randomly distributed along the horizontal direction perpendicular to the incident direction of the light. The active random refraction device can be switched between a transmission mode and a refractive mode according to the polarization of the light.

Abstract: Disclosed are a holographic writing method and apparatus capable of re-writing (updating) holographic information and quickly writing the holographic information with high efficiency. In an embodiment, a holographic writing method for writing holographic information by emitting a beam at a holographic recording medium containing a photo-responsable polymer material having photoisomerization characteristics that change a molecular structure thereof by absorbing light energy, writes the holographic information by using a writing wavelength different from a maximum absorption wavelength in a light absorption spectrum of photoisomer molecule structures of the holographic recording medium. The maximum absorption wavelength is a wavelength at which light absorption rate is maximum in the light absorption spectrum.

Abstract: Provided is a method for controlling liquid crystal alignment. An alignment film has a plurality of first grooves which are elongated in a first direction and area spaced from each other, and a plurality of second grooves which are elongated in a second direction and are spaced from each other by crossing said first grooves. Multistable liquid crystal alignment is enabled selectively by adjusting an aspect ratio of said first grooves and an aspect ratio of said second grooves.

Abstract: Provided is a polarization-dependent lens structure. The lens structure includes an optically-isotropic polymer layer having a reverse lens shape on a first surface and a lens portion where the surface of the optically-isotropic polymer layer is filled with liquid crystalline polymers, nano-scale 1D lattice structures (nano-scale grooves) are formed on an upper surface thereof, and the liquid crystalline polymers are aligned by the nano-scale 1D lattice structures along a direction of long axes of the 1D lattice structures, wherein it is determined according to a polarization direction of incident light whether or not the polarization-dependent lens structure operates as a lens.

Abstract: Provided is a polarization-dependent lens structure. The lens structure includes an optically-isotropic polymer layer having a reverse lens shape on a first surface and a lens portion where the surface of the optically-isotropic polymer layer is filled with liquid crystalline polymers, nano-scale 1D lattice structures (nano-scale grooves) are formed on an upper surface thereof, and the liquid crystalline polymers are aligned by the nano-scale 1D lattice structures along a direction of long axes of the 1D lattice structures, wherein it is determined according to a polarization direction of incident light whether or not the polarization-dependent lens structure operates as a lens.

Abstract: Provided is a method for controlling liquid crystal alignment. An alignment film has a plurality of first grooves which are elongated in a first direction and area spaced from each other, and a plurality of second grooves which are elongated in a second direction and are spaced from each other by crossing said first grooves. Mutilstable liquid crystal alignment is enabled selectively by adjusting an aspect ratio of said first grooves and an aspect ratio of said second grooves.