Speckle suppression of laser light using liquid crystals aligned by photoisomerization of dye molecules

Sueda, Keiichi; Tsubakimoto, Kouji; Miyanaga, Noriaki; Nakatsuka, Masahiro
December 2002
Applied Physics Letters;12/30/2002, Vol. 81 Issue 27, p5111
Academic Journal
For energy applications of high-power laser systems, uniform patterns are especially important in inertial confinement fusion research. We have demonstrated alignment control of liquid crystals using photoisomerization induced by polarized ultraviolet light to fabricate a polarization control plate. A glass substrate of a liquid-crystal cell, coated with polyvinyl alcohol doped with azo dye, was illuminated with a linearly polarized third harmonic of a Nd:YAG laser light. We confirmed the alignment of liquid crystals within the illuminated region dependent on the polarization direction of the ultraviolet light through the photoisomerization of azo dye molecules. Reduction of laser speckle pattern contrast by a polarization control plate was discussed.


Related Articles

  • Study of photoisomerization of azo dyes in liquid crystals. Statman, D.; Jánossy, I. // Journal of Chemical Physics;2/15/2003, Vol. 118 Issue 7, p3222 

    The trans-cis isomerization of azo dyes in liquid crystalline hosts is studied. It is shown that the full set of parameters governing the isomerization process can be deduced from polarized pump-probe transmission measurements. The results indicate that the dye order parameter for the trans...

  • Hybrid aligned cholesteric: A novel liquid-crystal alignment. Lewis, M. R.; Wiltshire, M. C. K. // Applied Physics Letters;10/12/1987, Vol. 51 Issue 15, p1197 

    A hybrid aligned cholesteric (HAC) liquid-crystal (LC) structure is reported. The LC director tilt varies from a small angle at one surface to almost 90° at the other, while incorporating a helical twist. Cells having one surface treated with rubbed polyvinyl alcohol and the other with the...

  • Indirect-drive radiation uniformity in tetrahedral hohlraums. Schnittman, J.D.; Craxton, R.S. // Physics of Plasmas;Oct96, Vol. 3 Issue 10, p3786 

    Studies indirect-drive radiation uniformity in tetrahedral hohlraums, a key element in the primary route to ignition and high gain in inertial confinement fusion. Beam ports provided to accommodate direct drive; Optimization of hohlraum designs using a three-dimensional view-factor program;...

  • Experimental studies of the advanced fast ignitor scheme. Norreys, P. A.; Allott, R.; Clarke, R. J.; Collier, J.; Neely, D.; Rose, S. J.; Zepf, M.; Santala, M.; Bell, A. R.; Krushelnick, K.; Dangor, A. E.; Woolsey, N. C.; Evans, R. G.; Habara, H.; Norimatsu, T.; Kodama, R. // Physics of Plasmas;Sep2000, Vol. 7 Issue 9 

    Guided compression offers an attractive route to explore some of the physics issues of hot electron heating and transport in the fast ignition route to inertial confinement fusion, whilst avoiding the difficulties associated with establishing the stability of the channel formation pulse. X-ray...

  • High-efficiency targets for high-gain inertial confinement fusion. Gardner, John H.; Bodner, Stephen E. // Physics of Fluids (00319171);Aug86, Vol. 29 Issue 8, p2672 

    Rocket efficiencies as high as 15% are possible using short wavelength lasers and moderately high aspect ratio pellet designs. These designs are made possible by two recent breakthroughs in physics constraints. First is the development of the induced spatial incoherence (ISI) technique, which...

  • Neutron time-of-flight signals from expanding or contracting spherical sources Murphy, T. J.; Chrien, R. E.; Klare, K. A. // Review of Scientific Instruments;Jan1997, Vol. 68 Issue 1, p614 

    Discusses neutron time-of-flight signals from expanding or contracting spherical sources in inertial confinement fusion. Details of the Los Alamos National Laboratory ion temperature diagnostic; Gas bag targets; Implosion with deuterated plastic shells.

  • Coded imaging of thermonuclear neutrons (invited). Nugent, K. A. // Review of Scientific Instruments;Aug1988, Vol. 59 Issue 8, p1658 

    Imaging of thermonuclear neutrons from inertial confinement fusion pellets is reviewed. The most promising technique, penumbral imaging, is discussed in detail and the design criteria are outlined. Simulations are presented. More advanced aspects are also briefly discussed, such as nonlinear...

  • Picosecond electrical characterization of x-ray microchannel-plate detectors used in diagnosing inertial confinement fusion experiments. Denysenko, A.; Alexandrou, S.; Wang, C.-C.; Bradley, D. K.; Donaldson, W. R.; Hsiang, T. Y.; Sobolewski, Roman; Bell, P. M. // Review of Scientific Instruments;Nov93, Vol. 64 Issue 11, p3285 

    The picosecond electrical pulse-propagation characteristics of microchannel-plate detectors, used in diagnosing laser-driven inertial-confmement-fusion experiments, were measured with an electro-optic sampling system. We determined propagation velocity and signal distortion of the...

  • Irradiation system based on dodecahedron for inertial confinement fusion. Murakami, M. // Applied Physics Letters;3/27/1995, Vol. 66 Issue 13, p1587 

    Focuses on the irradiation system based on the dodecahedral configuration for inertial confinement fusion. Discussion on the improvement of the number of beams, power imbalance and beam pattern; Achievement of high illumination uniformity; Effect of power imbalance on the uniformity.


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics