Imaging of fluorescence yield and lifetime from multiply scattered light re-emitted from random media

1997 ◽  
Author(s):  
Eva M. Sevick-Muraca ◽  
Dilip Y. Paithankar
Keyword(s):  
Random Media ◽  
Scattered Light ◽  
Fluorescence Yield

scholarly journals Fluorescent PIV using Atomized Liquid Particles

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Adit S. Acharya ◽  
K. Todd Lowe ◽  
Wing F. Ng
Keyword(s):  
Boundary Layer ◽  
Scattered Light ◽  
Adverse Pressure Gradient ◽  
Mie Scattering ◽  
Fluorescence Yield ◽  
Surface Measurement ◽  
Fluorescent Light ◽  
Near Surface ◽  
Freestream Velocity ◽  
Forward Facing Step

It is shown that aerosolized fluorescent particles generated using a Venturi-type atomizer, from a solution of fluorescent Kiton Red 620 dye in a water/glycol fluid, provide effective flow seeding for fluorescent PIV. The atomized liquid particles were found to be of acceptable size for PIV purposes, with 92% of detected particles by number concentration measuring < 1 μm in diameter. A PIV application was conducted in a wind tunnel (freestream velocity U∞ = 27 m/s), using the particles for measurement of the boundary layer flow approaching a forward-facing step (approach boundary layer momentum thickness Reynolds number of Reθ = 5930), to identify potential benefits in near-wall regions normally affected by unwanted laser reflections from tunnel surfaces. Particles were generated from solutions with dye molar concentrations of 2.5 × 10−3 and 1.0 × 10−2 mol/L, and PIV images were obtained for both elastic Mie scattering and filtered, Stokes-shifted fluorescent light. Raw images indicate that the fluorescence yield of the 1.0 × 10−2 mol/L solution provides PIV images with high contrast, even in the near-surface regions where Mie scattering images are highly affected by surface reflections. Boundary layer profiles are processed in the adverse pressure gradient region leading up to the forward-facing step, where the fluorescent PIV performed comparably to the most optimized Mie scattering PIV; both obtained data as near to the wall as 30 μm, or 2 viscous wall units in our flow of interest. These results indicate that the new seeding method holds excellent promise for near-surface measurement applications with more complicated three-dimensional geometries, where it is impossible to arrange PIV cameras to reject surface-scattered light.

scholarly journals Polarization control of multiply scattered light through random media by wavefront shaping

2012 ◽  
Vol 37 (22) ◽  
pp. 4663 ◽  
Author(s):  
Yefeng Guan ◽  
Ori Katz ◽  
Eran Small ◽  
Jianying Zhou ◽  
Yaron Silberberg
Keyword(s):  
Random Media ◽  
Scattered Light ◽  
Polarization Control ◽  
Wavefront Shaping

Imaging of fluorescent yield and lifetime from multiply scattered light reemitted from random media

1997 ◽  
Vol 36 (10) ◽  
pp. 2260 ◽  
Author(s):  
D. Y. Paithankar ◽  
A. U. Chen ◽  
B. W. Pogue ◽  
M. S. Patterson ◽  
E. M. Sevick-Muraca
Keyword(s):  
Random Media ◽  
Scattered Light

Random media with temperature controlled connectivity

1992 ◽  
Vol 2 (5) ◽  
pp. 503-510 ◽  
Author(s):  
F. Carmona ◽  
E. Valot ◽  
L. Servant ◽  
M. Ricci
Keyword(s):  
Random Media ◽  
Temperature Controlled

Magnetic resonance in the noise in the intensity of scattered light

1987 ◽  
Vol 153 (10) ◽  
pp. 363 ◽  
Author(s):  
Evgenii B. Aleksandrov ◽  
V.S. Zapasskii
Keyword(s):  
Magnetic Resonance ◽  
Scattered Light
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