Novel Azo Dye-Doped Poly(Methyl Methacrylate) Films as Optical Data Storage Media

Abstract

Azo dye-doped polymer (ADP) systems have been shown to be remarkable photosensitive media for holographic recording and optical computing. In this work we have studied the dynamic holographic capabilities of poly(methyl methacrylate) (PMMA) fims doped with five new azo dyes named AZD1-5. The totally reversible trans \rightleftharpoons cis photoisomerization induced by exposure of the ADP samples to actinic light allows recording of holograms in the dye-doped polymer matrices, and diffraction efficiencies up to 10% have been attained. These ADP systems can also be used to perform polarization holographic recordings as they present a photoinduced anisotropy called the Weigert effect. Depending on the intensity of the reading beam, the recorded information can be rapidly erased or stored for a posteriori use. The storage time can be as long as 800 s depending on the azo dye employed. These photosensitive materials can be classified as promising holographic media for optical computing and optical mass storage.

Holographic Recording in a Photoactive Elastomer

“…[1±4] Generally, the chromophore used is either doped in a polymer matrix [3,4] or covalently bounded to the polymer. [1,2] Azobenzene-containing polymers are among the most studied photoactive polymers.…”

Polymers and Dyes: Developments and Applications

“…Additional, cross-linked azo-polymers are known; however, cross-linking seems to depress the azo groups' isomerization ability. Azo dye doped polymers like poly(methyl methacrylate) can also be used as optical data storage media, but in these cases the chemical linking is negligible [109]. Some important side chain and main chain azo polymers are shown in Figure 10.…”

Azobenzene-Containing Materials for Hologram

“…Formation of holographic gratings in films of poly(vinyl alcohol) doped with low-molecular-weight AZ compounds was first reported by utilizing photoisomerization of AZs (Todorov et al, 1983(Todorov et al, , 1984(Todorov et al, , 1985. The holographic gratings recorded in the polymer-based samples were selfdeveloping and auto-erasing or re-writable since the thermally induced back isomerization of AZs could be easily obtained (Pham et al, 1997). To increase the formed birefringence |n 2 -n 1 | shown in Figure 2 and enhance the performance of recorded holograms, polymerdispersed AZ-containing low-molecular-weight LC compounds were also employed as recording media (Tondiglia et al, 1995).…”