With support from the Chemistry Research Instrumentation and Facilities Instrument Development program, Dr. Jennifer Ogilvie of the Department of Chemistry of the University of Michigan proposes to develop a Fourier transform tip-enhanced coherent anti-Stokes Raman scattering microscope (FT-TECARS). This instrument will provide chemically detailed characterization of samples, in the form of Raman spectra, with sub-diffraction-limited resolution of ~ 20 nm. The proposal aims to combine the scanning tip of an atomic force microscope to enhance the CARS signal, with a Michelson interferrometer to achieve high spectral resolution, and homodyne detection to increase discrimination against interference from far-field CARS background. The Fourier transform implementation, combined with the femtosecond laser for broad band excitation, will permit data collection over the finger print region. There are a number of research projects that could potentially benefit from such an instrument since it would allow one to gain insight into bonding and chemical properties of spatially minute surface structures. Dr. Ogilvie has decided the initial project for the FT-TECARS instrument to be the study phase behavior of model membranes composed of phospholipid/cholesterol mixtures.
