Polymer composites with azobenzene dyes and their metallic complexes are considered
as perspective media for polarization holography [1,2]. This holographic technique has many
unique properties and possibilities as compared to the scalar holography. These ones result in
advantages of polarization holographic information storage and in more flexible opportunities of
light beam control when using light polarization sensitive photoactive media.
There is considerable interest in the synthesis and characterization of azobenzene-containing
polymers because of their potential applications in photonic fields [3,4]. When irradiated with
linearly polarized light the long molecular axis of the azobenzene will be aligned perpendicular
to the electric field vector of the polarized actinic light through photochemical trans–cis–trans
isomerization cycles. This process results in optical anisotropy, which can be monitored by the
photoinduced birefringence measurements. Because of their unique properties, the polymers with
azobenzene chromophores are expected to be one of the most attractive materials for reversible
optical data storage media. However, most of the investigations focused on the single
azobenzene-based polymers. The films of copolymer octyl methacrylate with incorporated azo
dyes and its complex with Co were synthesized and investigated in the present work. Two azo
groups in the bisazobenzene derivatives can undergo photoisomerization and consequently
orientation under illumination with polarized light, which may increase the efficiency of
photoalignment and lead to novel optical properties. Presence of metallic ions opens additional
possibilities for control the electric, magnetic and optical properties of these polymer
composites, especially by external electric and/or magnetic field. Physical mechanisms of
formation of optical anisotropy in these media under influence of polarized light are described.
Experimental investigations of recording of the hologram of flat wave front in new
polymeric composites with azobenzene polycomplexes with coordinated metallic ions are done.
Conclusion about potential applicability of this medium for polarization holography is made.
References:
[1] Todorov, T.; Nikolova, L.; Tomova, N. In: Appl.Opt., 1984, 23, 4309.
[2] Yang, Q.; Wei, Z.; Zhang, Y.; Sun, G.; Li, F. In: Appl.Phys.B, 2001, 72, 855.
[3] Camorani, P.; Cristofolini, L.; Fontana, M.P.; Angiolini, L. In: Mol.Cryst.&Liq.Cryst., 2009,
500, 1.
[4] Ishitobi, H.; Tanbe, M. In: Optics Express, 2007, 15, 652.