Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Determination of 3-D molecular orientation by polarization broadband CARS spectroscopy

Published

Author(s)

Young J. Lee

Abstract

Theoretical description is presented about a new analysis method to determine 3-diminsional (3-D) molecular orientation by concurrently analyzing polarization profiles of multiple Raman modes measured by broadband coherent anti-Stokes Raman scattering (CARS) spectroscopy. Conventional analysis of polarization Raman spectroscopy is very limited in providing 3-D orientational information due to intrinsic nature of signal generation by 2-D rotating light polarization. Here we propose to use dimensionless quantities, such as intensity ratios and phase difference, observed from multiple polarization profiles simultaneously measured by a single polarization scanning of BCARS at a single location. We describe how 3-D molecular orientation can be determined from the mathematical relations between the dimensionless observables and orientational angles. The 3-D orientation measurement has been demonstrated for two simplified cases, both in the absence and in the presence of orientational broadening by using a model distribution function. Even in the presence of broadening, this analysis method can measure not only the mean 3-D orientation angles but also the degree of orientational broadening as defined in the model function.
Citation
Optics Express
Volume
23
Issue
22

Keywords

orientation, polarization, Raman, CARS

Citation

Lee, Y. (2015), Determination of 3-D molecular orientation by polarization broadband CARS spectroscopy, Optics Express, [online], https://doi.org/10.1364/OE.23.029279 (Accessed May 27, 2024)

Issues

If you have any questions about this publication or are having problems accessing it, please contact reflib@nist.gov.

Created October 30, 2015, Updated November 10, 2018