Experimental results on the photophoretic motion and radiometric trapping of particles by irradiation with laser light

1988 ◽  
Vol 47 (3) ◽  
pp. 247-250 ◽  
Author(s):  
S. De Nicola ◽  
A. Finizo ◽  
P. Mormile ◽  
G. Pierattini ◽  
S. Martellucci ◽  
...  
Keyword(s):  
Laser Light ◽  
Experimental Results

scholarly journals micro-Raman and micro-Photoluminescence study of ZnO thin films

2021 ◽  
Vol 24 (1) ◽  
pp. 1-8
Author(s):  
M.A. Urbina-Yarupetan ◽  
J.C. González
Keyword(s):  
Thin Films ◽  
Full Width Half Maximum ◽  
Laser Light ◽  
Experimental Results ◽  
Zno Thin Films ◽  
Full Width ◽  
Half Maximum ◽  
Optical Analysis ◽  
Photoluminescence Study ◽  
Commercial Glass

We present the experimental results of optical analysis of nanostructured ZnO thin films grown onto commercial glass by reactive sputtering. Films with 20, 50, and 100 nm in thickness were analyzed by micro-Raman and micro-photoluminescence spectroscopies. Raman and photoluminescence bands were deconvoluted with Lorentzian profiles, in order to obtain information about response of films to excitation with laser light, occurring changes in position, full width half maximum (FWHM), and area of each phonon and emission bands of ZnO, correlating them with its nanostructure nature, and packing morphology of ZnO nanocolumns.

Measurement of Nonuniform Stresses in Semiconductors by the Micro-Raman Method

1997 ◽  
Vol 505 ◽  
Author(s):  
K. Pinardi ◽  
S. C. Jain ◽  
H. E. Maes ◽  
R. Van Overstraeten ◽  
M. Willander ◽  
...  
Keyword(s):  
Absorption Coefficient ◽  
Laser Beam ◽  
Penetration Depth ◽  
Raman Spectra ◽  
Excellent Agreement ◽  
Large Volume ◽  
Strain Distribution ◽  
Laser Light ◽  
Experimental Results

ABSTRACTMicro-Raman measurements axe performed with a focused laser beam. Because of its finite diameter (∼ 1 μm) and penetration depth, the laser beam samples a “large volume” of the sample. In a nonuniformly strained sample, spectra originating from different points are different. Therefore the observed spectrum depends on both the strain distribution in the sample and the absorption coefficient of the laser light. We describe a method to calculate the Raman spectra taking these factors into account. The calculated spectra show excellent agreement with the experimental results.

Diagnostics of Gold Laser Plasmas

1988 ◽  
Vol 102 ◽  
pp. 357-360
Author(s):  
J.C. Gauthier ◽  
J.P. Geindre ◽  
P. Monier ◽  
C. Chenais-Popovics ◽  
N. Tragin ◽  
...  
Keyword(s):  
Experimental Results ◽  
Pure Gold ◽  
Electronic Temperature ◽  
X Ray ◽  
Laser Plasmas ◽  
Collisional Radiative Model ◽  
Radiative Model

AbstractIn order to achieve a nickel-like X ray laser scheme we need a tool to determine the parameters which characterise the high-Z plasma. The aim of this work is to study gold laser plasmas and to compare experimental results to a collisional-radiative model which describes nickel-like ions. The electronic temperature and density are measured by the emission of an aluminium tracer. They are compared to the predictions of the nickel-like model for pure gold. The results show that the density and temperature can be estimated in a pure gold plasma.

Observation of Phase Contrast Images in STEM and CTEM Modes by Using 100 kV Field Emission Electron Gun

1974 ◽  
Vol 32 ◽  
pp. 390-391
Author(s):  
Y. Harada ◽  
T. Goto ◽  
H. Koike ◽  
T. Someya
Keyword(s):  
Field Emission ◽  
Phase Contrast ◽  
Image Formation ◽  
Fresnel Diffraction ◽  
Experimental Results ◽  
Electron Gun ◽  
Scanning Microscopy ◽  
Emission Electron ◽  
Lattice Images

Since phase contrasts of STEM images, that is, Fresnel diffraction fringes or lattice images, manifest themselves in field emission scanning microscopy, the mechanism for image formation in the STEM mode has been investigated and compared with that in CTEM mode, resulting in the theory of reciprocity. It reveals that contrast in STEM images exhibits the same properties as contrast in CTEM images. However, it appears that the validity of the reciprocity theory, especially on the details of phase contrast, has not yet been fully proven by the experiments. In this work, we shall investigate the phase contrast images obtained in both the STEM and CTEM modes of a field emission microscope (100kV), and evaluate the validity of the reciprocity theory by comparing the experimental results.

Chronic Laser Exposure Effects on Rabbit Retina

1972 ◽  
Vol 30 ◽  
pp. 54-55
Author(s):  
Burton B. Silver ◽  
Theodore Lawwill
Keyword(s):  
Laser Irradiation ◽  
Laser Light ◽  
Broad Band ◽  
Argon Laser ◽  
Atropine Sulfate ◽  
Ultrastructural Changes ◽  
Laser Exposure ◽  
Rabbit Retina ◽  
Histological Changes ◽  
Threshold Doses

Dutch-belted 1 to 2.5 kg anesthetized rabbits were exposed to either xenon or argon laser light administered in a broad band, designed to cover large areas of the retina. For laser exposure, the pupil was dilated with atropine sulfate 1% and pheny lephrine 10%. All of the laser generated power was within a band centered at 5145.0 Anstroms. Established threshold for 4 hour exposures to laser irradiation are in the order of 25-35 microwatts/cm2. Animals examined for ultrastructural changes received 4 hour threshold doses. These animals exhibited ERG, opthalmascopic, and histological changes consistent with threshold damage.One month following exposure the rabbits were killed with pentobarbitol. The eyes were immediately enucleated and dissected while bathed in 3% phosphate buffered gluteraldehyde.

A new dissociation mode for dislocations in silicon

1978 ◽  
Vol 36 (1) ◽  
pp. 346-347
Author(s):  
A. Ourmazd ◽  
G.R. Booker ◽  
C.J. Humphreys
Keyword(s):  
Detailed Examination ◽  
Experimental Results ◽  
Dislocation Network ◽  
Weak Beam ◽  
Phosphorus Doped

A (111) phosphorus-doped Si specimen, thinned to give a TEM foil of thickness ∼ 150nm, contained a dislocation network lying on the (111) plane. The dislocation lines were along the three <211> directions and their total Burgers vectors,ḇt, were of the type , each dislocation being of edge character. TEM examination under proper weak-beam conditions seemed initially to show the standard contrast behaviour for such dislocations, indicating some dislocation segments were undissociated (contrast A), while other segments were dissociated to give two Shockley partials separated by approximately 6nm (contrast B) . A more detailed examination, however, revealed that some segments exhibited a third and anomalous contrast behaviour (contrast C), interpreted here as being due to a new dissociation not previously reported. Experimental results obtained for a dislocation along [211] with for the six <220> type reflections using (g,5g) weak-beam conditions are summarised in the table below, together with the relevant values.

Estimation of the noise in TEM image recorded on “imaging plate”

1987 ◽  
Vol 45 ◽  
pp. 748-749
Author(s):  
T. Oikawa ◽  
N. Mori ◽  
T. Katoh ◽  
Y. Harada ◽  
J. Miyahara ◽  
...  
Keyword(s):  
Low Dose ◽  
Quantum Noise ◽  
Laser Light ◽  
Imaging Plate ◽  
Total System ◽  
Electron Dose ◽  
X Ray ◽  
Image Recording ◽  
Recording Material ◽  
Highly Sensitive

The “Imaging Plate”(IP) is a highly sensitive image recording plate for X-ray radiography. It has been ascertained that the IP has superior properties and high practicability as an image recording material in a TEM. The sensitivity, one of the properties, is about 3 orders higher than that of conventional photo film. The IP is expected to be applied to low dose techniques. In this paper, an estimation of the quantum noise on the TEM image which appears in case of low electron dose on the IP is reported.In this experiment, the JEM-2000FX TEM and an IP having the same size as photo film were used.Figure 1 shows the schematic diagram of the total system including the TEM used in this experiment. In the reader, He-Ne laser light is scanned across the IP, then blue light is emitted from the IP.

Multislice calculations of RHEED patterns from vicinal Si (001)

1993 ◽  
Vol 51 ◽  
pp. 1000-1001
Author(s):  
Scott Lordi
Keyword(s):  
Misorientation Angle ◽  
Incident Angle ◽  
Incident Beam ◽  
Experimental Results ◽  
Bragg Condition ◽  
Vicinal Surfaces ◽  
Kinematic Theory ◽  
Step Edges

Vicinal Si (001) surfaces are interesting because they are good substrates for the growth of III-V semiconductors. Spots in RHEED patterns from vicinal surfaces are split due to scattering from ordered step arrays and this splitting can be used to determine the misorientation angle, using kinematic arguments. Kinematic theory is generally regarded to be inadequate for the calculation of RHEED intensities; however, only a few dynamical RHEED simulations have been attempted for vicinal surfaces. The multislice formulation of Cowley and Moodie with a recently developed edge patching method was used to calculate RHEED patterns from vicinal Si (001) surfaces. The calculated patterns are qualitatively similar to published experimental results and the positions of the split spots quantitatively agree with kinematic calculations.RHEED patterns were calculated for unreconstructed (bulk terminated) Si (001) surfaces misoriented towards [110] ,with an energy of 15 keV, at an incident angle of 36.63 mrad ([004] bragg condition), and a beam azimuth of [110] (perpendicular to the step edges) and the incident beam pointed down the step staircase.

Sign in / Sign up

Export Citation Format

Share Document