Abstract
Formation of spontaneous surface relief grating under pulsed exposure on the surface of an azo polymer film has been investigated. We did experiments in different repetition rates and pulse widths by use an electro mechanical chopper and a diode-pumped solid-state laser with wavelength of 532 nm as pump beam. Incidence of pump beam, has been set normal to the surface of azo-polymer film. Spontaneous surface relief grating with grating pitch of ~1,250 nm was formed. For low repetition rate, relaxation due to cis-trans isomerization becomes dominant and growth rate becomes slower. A threshold for spontaneous pattern formation was found. In addition to an increase in the diffraction intensity during illumination, anomalous variation of diffraction intensity by switching on and off the laser was observed. By switching off the recording beam sharp enhancement occurred. By switching on the recording beam, after a sharp decrease in the intensity of diffracted beam, it increased further under illumination. Anomalous variations, strongly depends on polarization of the probe beam and the irradiation time for the formation of spontaneous SRG. Sharp enhancement has been attributed to cis-trans thermal isomerization and sharp decrease has been attributed to isomeration in whole surface under illumination.
Similar content being viewed by others
References
Ahmadi Kandjani, S.: Self organized SRG formation on azo polymer thin film. Ph.D. Thesis, University of Angers, France (2007)
Barrett C.J., Natansohn A.L., Rochon P.L.: Mechanism of optically inscribed high-efficiency diffraction gratings in azo polymer films. J. Chem. Phys. 100, 8836–8842 (1996)
Barille R., Ahmadi-Kandjani S., Ortyl E., Kucharski S., Nunzi J.-M.: Cognitive ability experiment with photosensitive organic molecular thin films. Phys. Rev. Lett. 97, 048701 (2006)
Bian S., Williams J.M., Yu Kim D., Li L., Balasubramanian S., Kumar J., Tripathy S.: Photoinduced surface deformations on azobenzene polymer films. J. Appl. Phy. 86(8), 4498–4508 (1999)
Eichler H.J., Orlic S., Schulz R., Rübner J.: Holographic reflection gratings in azobenzene polymers. Opt. Lett. 26(9), 581–583 (2001)
Fan S., Shen D., Gu Y., Luo D.: Incoherent dark spatial solitons and guiding white light in photosensitive polymeric materials. Appl. Phys. B 101, 221–224 (2010)
Geue T., Henneberg O., Grenzer J., Pietsch U., Natansohn A., Rochon P., Finkelstein K.: Formation of a buried density grating on thermal erasure of azobenzene polymer surface gratings. Colloid Surf. A 198–200, 31–36 (2002)
Geue T.M., Henneberg O., Pietsch U., Natansohn A., Rochon P., Novikov D., Franz H.: X-ray investigations of formation efficiency of buried azobenzene polymer density gratings. J. Appl. Phys. 93, 3161–3166 (2003)
Hubert C. et al.: Spontaneous patterning of hexagonal structures in an azo-polymer using light-controlled mass transport. Adv. Mater. 14, 729–732 (2002)
Hubert C. et al.: Spontaneous photoinduced patterning of azo-dye polymer films: the facts. J. Opt. Soc. Am. B. 24(8), 1839–1846 (2007)
Leblond H. et al.: Spontaneous formation of optically induced surface relief gratings. J. Phys. B At. Mol. Opt. Phys. 42, 205401 (2009)
Lefin P., Fiorini C., Nunzi J.-M.: Anisotropy of the photoinduced translation diffusion of azobenzene-dyes in polymer matrices. Pure Appl. Opt. 7, 71–82 (1998)
Matsui T., Yamamoto S., Ozaki M., Yoshino K., Kajzar F.: Relaxation kinetics of photoinduced surface relief grating on azo polymer films. J. Appl. Phys. 92(12), 6959–6965 (2002)
Ortyl E., Kucharski S.: Refractive index modulation in polymeric photochromic films. Cent. Eur. J. Chem. 2, 137–159 (2003)
Rodringuez A., Vitrant G., Cholletand P.A., Kajzar F.: Photochromic properties of azo dye polymer thin films: evidence of an additional reversible mechanism of molecular behavior. Revista Mexicana DE FI′SICA 52, 135–138 (2006)
Sekkat Z., Knoll W.: Photoreactive Organic Thin films. Acadamic press, USA (2002)
Toodorov T., Nikolova L., Tomova N.: Polarization holography: a new high-efficiency organic material with reversible photoinduced birefringence. Appl. Opt. 23, 4309–4312 (1984)
Yager K.G., Barrett C.J.: Confinement of surface patterning in azo-polymer thin films. J. Chem. Phys. 126, 094908–094908-8 (2007)
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Mazaheri, L., Kandjani, S.A. Spontaneous nano pattern formation under pulsed exposure: relaxation kinetics study. Opt Quant Electron 44, 17–25 (2012). https://doi.org/10.1007/s11082-011-9525-0
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11082-011-9525-0