Fast Optical Recording of Polarization Holographic Grating Based on an Azo-Dye-Doped Polymer-Ball-Type Polymer-Dispersed Liquid Crystal Film

Abstract

Gallium phosphide (GaP) nanoparticles were synthesized by reacting GaCl 3 with Na 3 P in xylene. An electron spin resonance spectrum attributed to the Ga self-interstitial (Ga i ) defect in GaP nanoparticles was observed with factor g = 2.0028. From the ultraviolet and visible (UV-vis) spectrum it is inferred that GaP nanoparticles exhibit a direct transition and an indirect transition, and the blue-shifted band gaps are ascribed to the Ga i defect as well as the nanosize effect. In the Raman spectrum the transverse optical and longitudinal optical peaks have slight red shifts, which are attributed to the intrinsic impurities or defects in GaP nanoparticles. The Raman and infrared spectra both indicate that the surface optical (SO) phonon mode occurs in GaP nanoparticles. The SO mode originates from the defects on the surface of GaP nanoparticles. The optical properties associated with intrinsic defects hold promise for some potential applications in future nanodevices.

Polarization optics analogy of quantum wavefunctions in graphene

“…which describes the polarization state of an electromagnetic wave with electric field components along the x and y axes and The polarization state of light can be determined from interferometric and holographic measurements [13] or using space-variant subwavelength metal-stripe polarizers [14] in the spatial Fourier-transform polarimetry technique. Light polarization is essential in determining the dielectric constant of materials using ellipsometry [15], in polarization-sensitive optical coherence tomography [16], especially suited for examining biological samples, and in designing advanced devices such as polarization holographic gratings for fast optical recordings [17] and polarization-bistable lasers for optical memory [18].…”

Dielectric relaxation dynamics in liquid crystal – dye composites

“…Moreover, an extraordinarily high Kerr coefficient has been detected in a mixture of low-molar-mass NLC (5CB) and the azo dye C.I. Acid Red 2 [Methyl Red (MR) [14]]; this combination had attracted attention in the context of holographic gratings [15,16] including intensity gratings [17]. It has been demonstrated that a small amount of dye (w1%) dissolved in NLC enhances the reorientation of the NLC molecules by almost two orders of magnitude [18,19].…”

Liquid-crystal diffraction gratings using polarization holography alignment techniques

“…These two types of polarization holography have been applied to other photosensitive materials to create patterned alignment regions in azobenzenes, 22 dye-doped liquid crystals, 23 polymer liquid crystals, 24 and polymer-dispersed liquid crystals. [25][26][27] In our situation, the continuously varying polarization "imprint" on the alignment layers is most useful for aligning liquid crystal ͓Fig. 1͑c͔͒.…”