Relaxation Polarization Dependence of Circular Vector Gratings in Azobenzene Glassy Molecular Films

2020 ◽  
Vol 850 ◽  
pp. 285-290
Author(s):  
Andris Ozols ◽  
Peteris Augustovs ◽  
Kaspars Traskovskis ◽  
Valdis Kokars ◽  
Lauma Laipniece ◽  
...  
Keyword(s):  
Diffraction Efficiency ◽  
Relaxation Times ◽  
Grating Period ◽  
Volume Density ◽  
Laser Beams ◽  
Relaxation Polarization ◽  
Polarized Beam ◽  
Sandwich Type ◽  
Phd Thesis ◽  
532 Nm

Holographic grating recording and relaxation is studied in different azobenzene molecular glassy films by circularly orthogonally polarized 532 nm laser beams L and R. The readout was made by circularly polarized (R or L) 632.8 nm laser beam. Sandwich-type samples (glass-film-glass) were also studied. Maximum diffraction efficiency of 81% has been achieved in sandwich-type AR-173 film. The following relaxation features have been found: after reaching diffraction efficiency (DE) maximum no DE decay took place; DE read out by R-polarized beam was always higher than that by L-polarized beam; in sandwich-type samples DE decayed until zero when read out by R-polarization whereas DE was zero when read out by L-polarization. 50% relaxation times varied from 4 to 44 minutes, and they mainly decreased when grating period was increased. The observed relaxation peculiarities can be understood if one assumes that volume birefringence grating (VBG) is recorded followed by volume density grating (VDG) and surface relief grating (SRG) recording. R-polarization "feels" all gratings whereas L-polarization only VDG and SRG. At large exposures VDG and SRG dominate. These results confirm the conclusion made by J.Mikelsone in her 2018 PhD thesis that birefringence grating recording in azobenzene materials is a neccessary condition for SRG appearance.

scholarly journals Improvement in the diffraction efficiency of a polymer using an ionic liquid

2018 ◽  
Vol 83 (2) ◽  
pp. 213-220
Author(s):  
Sung Kim ◽  
Pankaj Attri ◽  
In Kim
Keyword(s):  
Diffraction Efficiency ◽  
Information Storage ◽  
Polymer Mixture ◽  
Dihydrogen Phosphate ◽  
Storage Devices ◽  
Dpss Laser ◽  
Photosensitive Polymer ◽  
Diode Pumped ◽  
First Time ◽  
532 Nm

In this paper, photosensitive materials for information storage devices are presented. The polymers were prepared using surface relief-grating (SRG) fabrication with a diode-pumped solid-state (DPSS) laser of 532 nm, and the diffraction efficiency (DE) of the polymers were assessed with a low-power DPSS laser at 633 nm. However, the diffraction efficiency of the azo-functionalized epoxy-based polymer was low, even after 15 min of exposure. To improve the efficiency and reduce the time it takes for the DE measurements of the photosensitive polymer, the polymer was combined ionic liquids (ILs). Various ILs, i.e., 1-methylimidazolium chloride ([Mim]Cl) from the imidazolium family of ILs and diethylammonium dihydrogen phosphate (DEAP), triethylammonium 4-aminotoluene-3-sulfonic acid (TASA) and tributylmethylammonium methyl sulphate (TBMS) from the ammonium family of ILs, were investigated. For the first time, it was observed that DE dramatically increased the DEAP?polymer mixture in 4 min compared to the polymer (alone) and other polymer?IL mixtures. Therefore, DEAP IL could help improve the efficiency of DE measurements in a shorter time.

scholarly journals Structural correlates of speed and endurance in skeletal muscle: the rattlesnake tailshaker muscle

1996 ◽  
Vol 199 (2) ◽  
pp. 351-358 ◽  
Author(s):  
P Schaeffer ◽  
K Conley ◽  
S Lindstedt
Keyword(s):  
Oxygen Uptake ◽  
Relaxation Times ◽  
High Volume ◽  
Volume Density ◽  
High Rate ◽  
Inner Mitochondrial Membrane ◽  
Single Motor Unit ◽  
Diamondback Rattlesnake ◽  
Atp Supply

The western diamondback rattlesnake Crotalus atrox can rattle its tail continuously for hours at frequencies approaching 90 Hz. We examined the basis of these fast sustainable contractions using electromyography, data on oxygen uptake and the quantitative ultrastructure of the tailshaker muscle complex. The tailshaker muscle has no apparent unique structures; rather, the relative proportions of the structures common to all skeletal muscles appear to be present (1) to minimize activation, contraction and relaxation times via an extremely high volume density of sarcoplasmic reticulum (26 %) as well as, (2) to maximize ATP resysnthesis via a high volume density of mitochondria (26 %). The high rate of ATP supply is reflected in the in vivo muscle mass-specific oxygen uptake of this group of muscles which, at 585 ml O2 kg-1 min-1 during rattling at 30 °C body temperature, exceeds that reported for other ectotherm and many endotherm muscles. Since the change in oxygen uptake paralleled that of the rattling frequency over the range of measured body temperatures, there was a nearly constant O2 cost per muscle contraction (0.139±0.016 µl O2 g-1). Electromyo-graphic analysis suggests that each of the six muscles that make up the shaker complex may be a single motor unit. Finally, the maximum rate of mitochondrial oxygen uptake is similar to that of various mammals, a hummingbird, a lizard, an anuran amphibian and of isolated mitochondria (at 10 000-40 000 molecules O2 s-1 µm2 of cristae surface area, when normalized to 30 °C), suggesting a shared principle of design of the inner mitochondrial membrane among the vertebrates.

Time-delayed Three-wave Mixing of Nanosecond Incoherent Laser Beams for Measuring Short Relaxation Times

1988 ◽  
Vol 35 (12) ◽  
pp. 1933-1937 ◽  
Author(s):  
P.A. Apanasevich ◽  
V.P. Kozich ◽  
A.I. Vodschitz
Keyword(s):  
Relaxation Times ◽  
Laser Beams ◽  
Wave Mixing

OPTICALLY-OPERATED ELASTOOPTICAL EFFECTS IN POLYMER MATRICES WITH NANOCRYSTALLITES

2011 ◽  
Vol 04 (04) ◽  
pp. 357-359 ◽  
Author(s):  
I. V. KITYK ◽  
N. ALZAYED ◽  
A. H. RESHAK ◽  
K. J. PLUCINSKI ◽  
J. BERDOWSKI ◽  
...  
Keyword(s):  
Polymer Nanocomposites ◽  
Polymer Matrices ◽  
Laser Beams ◽  
Optical Treatment ◽  
Nanoparticle Content ◽  
532 Nm

We have found that the optical treatment by bicolor two laser beams at 1064 and 532 nm, at energy densities 80–120 mJ/cm2 originating from the same 10 ns Nd3+ garnett lasers causes the occurrence of the piezooptical effect in 50–80 nm γ-glicyne polymer nanocomposites at nanoparticle content about 6.5% in weighting unit. We propose to use this effect for optical triggers.

The Effect of Laser Wavelength and Concentration on Thermal Nonlinear Refractive Index of Graphene Suspensions

NANO ◽  
2015 ◽  
Vol 10 (04) ◽  
pp. 1550053 ◽  
Author(s):  
A. Arandian ◽  
R. Karimzadeh ◽  
S. Y. Faizabadi
Keyword(s):  
Refractive Index ◽  
Nonlinear Refractive Index ◽  
Continuous Wave ◽  
Concentration Level ◽  
Laser Wavelength ◽  
Laser Beams ◽  
Power Laser ◽  
Wave Regime ◽  
532 Nm ◽  
Concentration Levels

In this work, the nonlinear refractive properties of graphene suspension at different concentration levels are investigated by means of Z-scan technique with continuous wave low power laser beams at 532 nm and 635 nm. Results show that the dispersion of graphene in water exhibits negative nonlinear refractive index in continuous wave regime, which is mainly attributed to thermal nonlinear effect. We find that the absorption coefficient and nonlinear refractive index of the samples increase with increasing the concentration level of the graphene. Moreover, it is obtained that the nonlinear refractive index of the samples at different concentration levels depends on the wavelength of laser beam.

scholarly journals The parameters effect on the holographic optical elements

2011 ◽  
Vol 8 (2) ◽  
pp. 429-434
Author(s):  
Baghdad Science Journal
Keyword(s):  
Diffraction Efficiency ◽  
Diffraction Grating ◽  
Optical Element ◽  
Band Width ◽  
Optical Elements ◽  
Yag Laser ◽  
Holographic Optical Element ◽  
Dichromated Gelatin ◽  
532 Nm ◽  
Grating Thickness

In this work we fabrication holographic optical element diffraction grating thickness 40?m and mirror90?m by using dichromated gelatin,to perform that we have to use the Nd-yaG laser doubling frequency of wavelenght (532)nm and its powers of (80)mWatt.we have studyed the thickness and concentration dichromat effect in mirror reflaction ,effect of angle of reconstruction beam in band width and diffraction efficiency ,study effect gelatin hardener of the diffraction efficiency.

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