Difference between revisions of "Hyper Rayleigh Scattering"

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Hyper Rayleigh Scattering (aka Harmonic Light Scattering) is one method for measuring β.  
Hyper Rayleigh Scattering (aka Harmonic Light Scattering or HRS) is one method for measuring the [[first hyperpolarizability]]β. Another method is electric field induced second harmonic generation (EFISH)


=== Overview ===
=== Overview ===
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[[Image:Hrs.png|thumb|400px|Schematic of the HRS setup. CL = collimating lenses; LPF = long-pass filter; FL = 300-mm focusing lens; S = solution of chromophore in solvent of choice; DO = detection optics; IF = interference filter (950 nm)]]
[[Image:Hrs.png|thumb|400px|Schematic of the HRS setup. CL = collimating lenses; LPF = long-pass filter; FL = 300-mm focusing lens; S = solution of chromophore in solvent of choice; DO = detection optics; IF = interference filter (950 nm)]]


An incident laser generates a second harmonic signal, specifically the frequency double signal. This can be related to the beta of the sample using this formula:
A dilute sample of test chromophore is prepared in a solvent. The
In HRS an incident laser generates a second harmonic signal, specifically the frequency double signal. This can be related to the beta of the sample using this formula:


:<math>\frac {I_{sample}} {I_{solvent}} =  \frac {N_{sample} \langle \beta^2 _{sample} \rangle  + N_{solvent} \langle \beta^2_{solvent}\rangle}  {N_{solvent} \langle \beta^2_{solvent}\rangle}\,\!</math>
:<math>\frac {I_{sample}} {I_{solvent}} =  \frac {N_{sample} \langle \beta^2 _{sample} \rangle  + N_{solvent} \langle \beta^2_{solvent}\rangle}  {N_{solvent} \langle \beta^2_{solvent}\rangle}\,\!</math>

Revision as of 10:54, 12 October 2009

Hyper Rayleigh Scattering (aka Harmonic Light Scattering or HRS) is one method for measuring the first hyperpolarizabilityβ. Another method is electric field induced second harmonic generation (EFISH)

Overview

Schematic of the HRS setup. CL = collimating lenses; LPF = long-pass filter; FL = 300-mm focusing lens; S = solution of chromophore in solvent of choice; DO = detection optics; IF = interference filter (950 nm)

A dilute sample of test chromophore is prepared in a solvent. The In HRS an incident laser generates a second harmonic signal, specifically the frequency double signal. This can be related to the beta of the sample using this formula:

<math>\frac {I_{sample}} {I_{solvent}} = \frac {N_{sample} \langle \beta^2 _{sample} \rangle + N_{solvent} \langle \beta^2_{solvent}\rangle} {N_{solvent} \langle \beta^2_{solvent}\rangle}\,\!</math>
HRS spectrum for 1.5 μm TCP1 in CHCl3

See Firestone 2004 [1].


See Wikipedia on Rayleigh Scattering

See also Density Functional Theory

Technique

Video to come

Significance

References

  1. K. A. Firestone, P. Reid, R. Lawson, S. H. Jang, and L. R. Dalton, “Advances in Organic Electro-Optic Materials and Processing,” Inorg. Chem. Acta, 357, 3957-66 (2004)