scholarly journals Investigating the effects of laser beams (532 nm and 660 nm) in annihilation of pistachio mould fungus using spectrophotometry analysis

2010 ◽  
Vol 5 ◽  
Author(s):  
Saiedeh Saghafi ◽  
Rozhin Penjweini ◽  
Klaus Becker ◽  
Karl W. Kratky ◽  
Hans-Ulrich Dodt
Keyword(s):  
Laser Beams ◽  
Mould Fungus ◽  
532 Nm

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.

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.

D–D–A dyes with phenothiazine–carbazole/triphenylamine as double donors in photopolymerization under 455 nm and 532 nm laser beams

2016 ◽  
Vol 7 (31) ◽  
pp. 5039-5049 ◽  
Author(s):  
T. F. Zhou ◽  
X. Y. Ma ◽  
W. X. Han ◽  
X. P. Guo ◽  
R. Q. Gu ◽  
...  
Keyword(s):  
Organic Dyes ◽  
Electron Donors ◽  
Laser Beams ◽  
Double Electron ◽  
532 Nm

In order to enhance electron-donating ability, four novel organic dyes (CPC, TPC, CPN and TPN) with double electron donors have been designed and synthesized.

scholarly journals Rotation of two-petal laser beams in the near field of a spiral microaxicon

2018 ◽  
Vol 42 (3) ◽  
pp. 385-391 ◽  
Author(s):  
S. S. Stafeev ◽  
L. O'Faolain ◽  
M. V. Kotlyar
Keyword(s):  
Electron Beam Lithography ◽  
Rotation Rate ◽  
Topological Charge ◽  
Near Field ◽  
Laser Beams ◽  
Beam Path ◽  
Rotation Rates ◽  
Final Segment ◽  
Simulation Results ◽  
532 Nm

Using a spiral microaxicon with the topological charge 2 and NA = 0.6 operating at a 532-nm wavelength and fabricated by electron-beam lithography, we experimentally demonstrate the rotation of a two-petal laser beam in the near field (several micrometers away from the axicon surface). The estimated rotation rate is 55 °/μm and linearly dependent on the on-axis distance, with the theoretical rotation rate being 53 °/μm. The experimentally measured rotation rate is found to be linear and coincident with the simulation results only on the on-axis segment from 1.5 to 3 μm. The experimentally measured rotation rate is 66 °/μm on the initial on-axis segment from 0 to 1.5 μm and 34 °/μm on the final segment of the beam path from 3 to 4.5 μm. The experimentally achieved rotation rate is higher than rotation rates of similar two-petal laser beams reported to date.

Mode designations of laser beams

1985 ◽  
Vol 132 (3) ◽  
pp. 191 ◽  
Author(s):  
Luk Kwai-Man ◽  
Yu Ping-Kong
Keyword(s):  
Laser Beams

Prospects of development of the reference base of the Russian Federation in the field of length measurements

2020 ◽  
pp. 3-5
Author(s):  
Y. G. Zakharenko ◽  
N. A. Kononova ◽  
V. L. Fedorin ◽  
Z. V. Fomkina ◽  
K. V. Chekirda
Keyword(s):  
High Precision ◽  
Russian Federation ◽  
Reference Base ◽  
Length Measurements ◽  
Laser Sources ◽  
The Russian Federation ◽  
Unit Of Length ◽  
Further Development ◽  
532 Nm

The results of the work to create a complex of high-precision hardware for the unit of length reproduction and transferring carried out at “D. I. Mendeleyev Institute for Metrology (VNIIM)” are represented. This complex will serve as the basis for the further development of the reference base of the Russian Federation in the field of length measurements and will allow reproduction of the unit of length at two wavelengths of 633 nm and 532 nm, as well as measurements of the wavelength of laser sources in vacuum in the range from 500 to 1050 nm.

Linear and Nonlinear Optical Properties of Natural Dyes Freestanding Films and Application in Optical Limiting

2020 ◽  
pp. 139-143
Keyword(s):  
Absorption Coefficient ◽  
Water Solution ◽  
Optical Limiting ◽  
Refraction Index ◽  
Laser Wavelength ◽  
Solid State Laser ◽  
Natural Dyes ◽  
Linear And Nonlinear ◽  
532 Nm ◽  
Absorbance Spectra

Natural dyes were followed and prepared from a pomegranate, purple carrot, and eggplant peel. The absorbance spectra was measured in the wavelength range 300-800 nm. The linear properties measurements of the prepared natural dye freestanding films were determined include absorption coefficient (α0), extinction coefficient (κ), and linear refraction index (n). The nonlinear refractive index n2 and nonlinear absorption coefficient β2 of the natural dyes in the water solution were measured by the optical z-scan technique under a pumped solid state laser at a laser wavelength of 532 nm. The results indicated that the pomegranate dye can be promising candidates for optical limiting applications with significantly low optical limiting of 3.5 mW.

Sign in / Sign up

Export Citation Format

Share Document