Correlation between photoconductivity and holographic response time in a photorefractive guest host polymer

Synthesis and characterization of novel photoconducting carbazole derivatives in main-chain polymers for photorefractive applications

“…After a period of 200 s, a second writing beam was applied, and the diffracted reading beam monitored. The time constants, t 1 (the fast time constant, corresponding to the time of internal electric field build-up) and t 2 (the slow time constant, corresponding to the reorientation time of the internal space-charge field), were calculated by fitting the evolution of the growth of the diffraction signal, h(t) [7]. The response time of the diffraction efficiency increased as the temperature increased above the polymer composite T g value.…”

<title>Photoconductivity and charge-carrier photogeneration in photorefractive polymers</title>

“…For the build-up of the refractive index grating the following processes are necessary: (i) photogeneration of charge carriers, (ii) diffusion or drift of the mobile charge carriers, (iii) trapping of these charge carriers in the regions of low light intensity and (iv) change of the index of refraction due to the build-up of an internal space-charge field. To relate a material's PR performance to these fundamental processes, (i) and (ii) can be studied by photoconductivity [1][2][3] . The electro-optical response has been investigated with ellipsometric techniques 4 .…”

Photorefractivity of Poly[methyl(3-phenothiazine-10-ylpropyl) siloxane] doped with chromophore and C60

“…After 200 s, the other writing beam was applied and the diffracted reading beam was monitored. Time constants s were calculated by fitting the evolution of the growth of the diffraction signal, g(t) [11]. We obtained exhibit the response time s 1 of 4.2 s for the PSX-PTZ composite under T g + 2°C.…”

“…The diffraction efficiency of PR material was determined by the degenerated four wave mixing (DFWM) experiment [11]. Two coherent laser beams at the wavelength of 633 nm were irradiated on the sample in the tilted geometry with the incident angle of 30°and 60°with respect to a sample normal.…”