Optical, electrical, and photophysical properties of films of polycomplexes of azobenzene derivatives with cobalt

Films made of substituted azobenzene polycomplexes with cobalt for polarization holography

“…But if immediately after exposure of the holo- Fig. 1 Hologram recording (1, 2) and relaxation (3)(4)(5)(6) kinetics in the case E 1 N E 2 (1, 3, 5) and E 1 M E 2 (2,4,6); curves 3, 4 were obtained using the reference beam after exposure and storage of the recording media in the dark; curves 5, 6 were obtained when reading with the reference beam immediately after exposure, exposure time 1.5⋅10 3 sec. gram, the polymer film is briefly heated above the glass transition temperature, then this may result in fixation and long-term preservation of the hologram recording [15].…”

“…Films of polymer composites with azo dye monomers or containing azobenzene side groups chemically bonded to the polymer backbone have optically active properties, which can be used to design electro-optical light modulators [1,2] and holographic recording media [3][4][5][6][7]. When these films are exposed to linearly polarized light, photoinduced optical anisotropy appears, which is caused by a change in the concentrations of trans and cis isomers of the azobenzene groups.…”

Electro-optical properties and photopolarization anisotropy of methacrylic azopolymer films

“…In an external electric field, rotation of the isomers of the azobenzene groups occurs. Since the mechanism for the effect of an electric field is connected with the appearance of forces orienting the dipole moments of the azo compounds, the electro-optic effect appears in polymers with azo side groups [13]. However, to date there has been no study in the literature of the question of the effect of the length of the "spacer" (the group of atoms linking the azobenzene moiety with the polymer backbone) on the electro-optical and photo-dielectric properties of methacrylic azopolymer films.…”

“…The procedure for preparing the samples is described in [13]. The thickness of the polymer film was 2-3 μm.…”

“…Owing to the fact that the dipole moment of the optical transition of the dyes is oriented approximately along their long molecular axis, absorption of light by the molecules depends essentially on the angle between the axis of the molecule and the electric polarization vector of the light. Therefore polymer composites based on azo dyes can be used as optically active media for recording optical polarization holograms, obtaining liquid-crystal structures and materials for recording information [4][5][6][7][8][9][10][11][12][13]. The induced polarization can be changed by means of external thermal or mechanical treatment (on heating or exposure to light, in an external electric field).…”