scholarly journals Influence of the probe beam size on the photothermal reflectance signal

1994 ◽  
Vol 04 (C7) ◽  
pp. C7-19-C7-22 ◽  
Author(s):  
T. Velinov ◽  
G. Burov ◽  
K. Bransalov ◽  
J.-P. Roger ◽  
A. Mansanares
Keyword(s):  
Probe Beam ◽  
Beam Size

Photothermal beam-deflection imaging of vertical interfaces in solids

1986 ◽  
Vol 64 (9) ◽  
pp. 1265-1268 ◽  
Author(s):  
F. Alan McDonald ◽  
Grover C. Wetsel Jr. ◽  
Georges E. Jamieson
Keyword(s):  
Probe Beam ◽  
New Method ◽  
Beam Deflection ◽  
Beam Size ◽  
Thermal Barriers

A new method for calculating signals in photothermal beam-deflection imaging is reviewed and applied to the case of vertical interfaces (cracks or other thermal barriers) in opaque solids. The generality of the approach and the effect of finite probe-beam size are emphasized.

Thermal Expansion-Recovery Microscopy (ThERM) for microstructural characterization

2013 ◽  
Vol 1526 ◽  
Author(s):  
Esteban A. Domené ◽  
Nélida Mingolo ◽  
Oscar E. Martínez
Keyword(s):  
Thermal Expansion ◽  
Thermal Diffusivity ◽  
Probe Beam ◽  
Pump Beam ◽  
Surface Deformation ◽  
Modulation Frequency ◽  
Microstructural Characterization ◽  
Sample Surface ◽  
Beam Size ◽  
Detection Schemes

ABSTRACTIn this work we compare two different detection schemes that are sensitive to the focus shift of a probe beam due to induced surface curvature. The technique on which both detection schemes are based is called ThERM (Thermal Expansion-Recovery Microscopy) and allows the retrieval of the thermal diffusivity at microscopic levels, hence mapping such magnitude over a sample surface. The induced thermal expansion defocuses the probe beam due to the surface deformation (curvature). The dependence of the defocusing with the pump modulation frequency yields the thermal diffusivity of the sample at the impinging location. The explored depth is controlled by the pump beam size. By scanning both beams, a complete map of the thermal diffusivity can be retrieved.

Probe beam size effect on the measurement of the distance between the probe beam and the sample in photothermal deflection

2006 ◽  
Vol 31 (1) ◽  
pp. 44 ◽  
Author(s):  
Jurandir H. Rohling ◽  
Jun Shen ◽  
Jianqin Zhou ◽  
Caikang Elton Gu
Keyword(s):  
Size Effect ◽  
Probe Beam ◽  
Beam Size ◽  
Photothermal Deflection

Probe beam size effects in photothermal deflection experiments

1988 ◽  
Vol 64 (1) ◽  
pp. 1-5 ◽  
Author(s):  
E. Legal Lasalle ◽  
F. Lepoutre ◽  
J. P. Roger
Keyword(s):  
Probe Beam ◽  
Size Effects ◽  
Beam Size ◽  
Photothermal Deflection

Arsenic segregation in polysilicon

1983 ◽  
Vol 41 ◽  
pp. 154-155 ◽  
Author(s):  
P.E. Batson ◽  
C.R.M. Grovenor ◽  
D.A. Smith ◽  
C. Wong
Keyword(s):  
Incident Beam ◽  
Silicon Wafers ◽  
Chemical Polishing ◽  
Bright Field Image ◽  
Beam Size ◽  
Stem Analysis ◽  
Bright Field ◽  
Twin Boundaries ◽  
X Ray ◽  
Line Scan

In this work As doped polysilicon was deposited onto (100) silicon wafers by APCVD at 660°C from a silane-arsine mixture, followed by a ten minute anneal at 1000°C, and in one case a further ten minute anneal at 700°C. Specimens for TEM and STEM analysis were prepared by chemical polishing. The microstructure, which is unchanged by the final 700°C anneal,is shown in Figure 1. It consists of numerous randomly oriented grains many of which contain twins.X-ray analysis was carried out in a VG HB5 STEM. As K α x-ray counts were collected from STEM scans across grain and twin boundaries, Figures 2-4. The incident beam size was about 1.5nm in diameter, and each of the 20 channels in the plots was sampled from a 1.6nm length of the approximately 30nm line scan across the boundary. The bright field image profile along the scanned line was monitored during the analysis to allow correlation between the image and the x-ray signal.

Pump-Probe Measurements Using Silicon Nanocrystal Waveguides

2003 ◽  
Vol 770 ◽  
Author(s):  
Nathanael Smith ◽  
Max J. Lederer ◽  
Marek Samoc ◽  
Barry Luther-Davies ◽  
Robert G. Elliman
Keyword(s):  
Probe Beam ◽  
Time Resolution ◽  
Pump Beam ◽  
Silicon Nanocrystals ◽  
Continuous Wave ◽  
Optical Gain ◽  
Optical Pump ◽  
Time Resolved ◽  
Pump Probe ◽  
Probe Measurements

AbstractOptical pump-probe measurements were performed on planar slab waveguides containing silicon nanocrystals in an attempt to measure optical gain from photo-excited silicon nanocrystals. Two experiments were performed, one with a continuous-wave probe beam and a pulsed pump beam, giving a time resolution of approximately 25 ns, and the other with a pulsed pump and probe beam, giving a time resolution of approximately 10 ps. In both cases the intensity of the probe beam was found to be attenuated by the pump beam, with the attenuation increasing monotonically with increasing pump power. Time-resolved measurements using the first experimental arrangement showed that the probe signal recovered its initial intensity on a time scale of 45-70 μs, a value comparable to the exciton lifetime in Si nanocrystals. These data are shown to be consistent with an induced absorption process such as confined carrier absorption. No evidence for optical gain was observed.

scholarly journals Giant Molecular Cloud Formation at the Interface of Colliding Supershells in the Large Magellanic Cloud

2021 ◽  
Author(s):  
Kosuke Fujii ◽  
Norikazu Mizuno ◽  
J R Dawson ◽  
Tsuyoshi Inoue ◽  
Kazufumi Torii ◽  
...  
Keyword(s):  
Large Magellanic Cloud ◽  
Cloud Formation ◽  
Beam Size ◽  
Star Forming ◽  
Star Forming Regions ◽  
Long Baseline ◽  
Gravitational Instabilities ◽  
Atomic Medium ◽  
High Column ◽  
Compact Array

Abstract We investigate the H i envelope of the young, massive GMCs in the star-forming regions N48 and N49, which are located within the high column density H i ridge between two kpc-scale supergiant shells, LMC 4 and LMC 5. New long-baseline H i 21 cm line observations with the Australia Telescope Compact Array (ATCA) were combined with archival shorter baseline data and single dish data from the Parkes telescope, for a final synthesized beam size of 24.75″ by 20.48″, which corresponds to a spatial resolution of ∼ 6 pc in the LMC. It is newly revealed that the H i gas is highly filamentary, and that the molecular clumps are distributed along filamentary H i features. In total 39 filamentary features are identified and their typical width is ∼ 21 (8–49) [pc]. We propose a scenario in which the GMCs were formed via gravitational instabilities in atomic gas which was initially accumulated by the two shells and then further compressed by their collision. This suggests that GMC formation involves the filamentary nature of the atomic medium.

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