A dynamic beam splitter using polymer dispersed liquid crystal materials

Abstract

We build a dynamic beam splitter with a holographic optical element (HOE). The laser light goes through the HOE and a fraction of intensity diffracted and transmitted could be tuned by an electric signal. We use holographic polymer dispersed liquid crystals materials. It is made by holographic recording in which the liquid crystal molecules diffuse to dark zones in the diffraction grating and they can be oriented by means of an electric field. The orientation of the liquid crystal produces a refraction index variation which changes the diffraction efficiency and therefore the grating has a dynamic behavior.

Ultra-Thin Metamaterial Beam Splitters

“…The designed beam splitters can be integrated with other components for compact optical and photonic devices and systems. The tunability of the designed fishnet based beam splitters can be possible through, for example, voltage-tunable nematic liquid crystals [30], thermally-tunable property of physical systems with nematic liquid crystal mixtures [31], electro-optically tunable liquid crystals [13,32,33], and temperature using an external laser [34]. There exist theoretically proposed [35,36] and experimentally realized [37][38][39], even around 1.55 µm wavelength [38], tunable fishnet metamaterials based on liquid crystals [35,[37][38][39] and temperature [36].…”

“…In earlier works, PBS designs based on an Ag mirror embedded in silica grating [9] and perforated GaAs photonic crystal [10] were theoretically proposed and experimentally realized with gratings etched in a TiO 2 layer on a glass substrate fabricated by electron-beam writing and reactive ion etching [11]. Other interesting designs that were demonstrated include a PBS cube for arbitrary orthogonal polarizations based on liquid crystal polymer layers [12] and electrically tunable beam splitters employing polymer dispersed liquid crystals [13].…”

Spatial Frequency Responses of Anisotropic Refractive Index Gratings Formed in Holographic Polymer Dispersed Liquid Crystals

“…Such electro-optic HPDLCs consist of LCs incorporated into photopolymer followed by holographic polymerization that represents a fast and relatively simple way of fabricating multi-dimensional refractive index grating structures for electrically switchable and tunable photonic devices [ 7 ]. They have been used for wavelength filters, 3D displays, hyperspectral imaging, optical beam switching/control devices, sensors, lasers, optical memory and photonic crystals [ 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 ].…”