Biomedical subjects

Nadia Belabas

Publications and source records attributed to Nadia Belabas.

3 recordsLinked to original sources

PubMed2005

2D correlation analysis of the continuum in single molecule surface enhanced Raman spectroscopy.

The role and the nature of the continuum in Surface Enhanced Raman Spectroscopy (SERS) are unclear. Here, two-dimensional (2D) covariance and correlation analysis is applied to single molecule SERS spectra on silver colloids with and without rhodamine 6G (native colloid). The resulting 2D covariance and correlation maps show that the sharp molecular Raman peaks from rhodamine 6G and the molecule responsible for the SERS peaks from the native colloid are correlated to different continua even though both continua are present in each data set. This suggests that two distinct active sites on the silver colloids produce the two different continua, and that each site has some molecular specificity.

Journal Article↗

PubMed2005

Mid-infrared electric field characterization using a visible charge-coupled-device-based spectrometer.

We characterize ultrashort mid-infrared pulses through upconversion by using the stretched pulses obtained from the uncompressed output of a chirped-pulse amplifier. The power spectrum thus translated into the visible region can be readily measured with a standard silicon CCD camera-based spectrometer. The spectral phase is also characterized by a variant of zero-added-phase spectral phase interferometry for direct electric field reconstruction. This is a general method that provides a multiplex advantage over conventional infrared detector array-based methods.

Journal Article↗

PubMed2004

Fourier algorithm for four-wave-mixing signals from optically dense systems with memory.

A triple Fourier-transform algorithm for generating and propagating femtosecond four-wave-mixing signals in optically thick samples is demonstrated. The algorithm has a dynamic range that is useful for tests of theory and simulations of experiments with an arbitrary nonlinear response. Although two-pulse echoes decay faster as optical density increases for a Bloch model, we find that systems with memory exhibit the opposite trend.

Journal Article↗