Measurements of nonlinear refractive index in scattering media.
Abstract
We have recently developed a spectral re-shaping technique to simultaneously measure
nonlinear refractive index and nonlinear absorption. In this technique, the information
about the nonlinearities is encoded in the frequency domain, rather than in the spatial
domain as in the conventional Z-scan method. Here we show that frequency encoding
is much more robust with respect to scattering. We compare spectral re-shaping and
Z-scan measurements in a highly scattering environment and show that reliable spectral
re-shaping measurements can be performed even in a regime that precludes standard
Z-scans.
Type
Journal articlePermalink
https://hdl.handle.net/10161/4246Collections
More Info
Show full item recordScholars@Duke
Martin Fischer
Research Professor in the Department of Chemistry
Dr. Fischer’s research focuses on exploring novel nonlinear optical contrast mechanisms
for molecular imaging. Nonlinear optical microscopes can provide non-invasive, high-resolution,
3-dimensional images even in highly scattering environments such as biological tissue.
Established contrast mechanisms, such as two-photon fluorescence or harmonic generation,
can image a range of targets (such as autofluorescent markers or some connective tissue
structure), but many of the most molecularly specif
Warren S. Warren
James B. Duke Distinguished Professor of Chemistry
Our work focuses on the design and application of what might best be called novel
pulsed techniques, using controlled radiation fields to alter dynamics. The heart
of the work is chemical physics, and most of what we do is ultrafast laser spectroscopy
or nuclear magnetic resonance. It generally involves an intimate mixture of theory
and experiment: recent publications are roughly an equal mix of pencil- and-paper
theory, computer calculations with our workstations, and experiments. Collabo
Alphabetical list of authors with Scholars@Duke profiles.

Articles written by Duke faculty are made available through the campus open access policy. For more information see: Duke Open Access Policy
Rights for Collection: Scholarly Articles
Works are deposited here by their authors, and represent their research and opinions, not that of Duke University. Some materials and descriptions may include offensive content. More info