Multi-dimensional differential imaging with FE-CARS microscopy

Focus-engineered coherent anti-Stokes Raman scattering (FE-CARS) microscopy is used to visualize microscopic samples with differential imaging contrast in both longitudinal and lateral directions. Multidimensional contrast is achieved by applying a one-dimensional p-phase step in the transverse beam profile of the Stokes beam. The observed longitudinal differential contrast results from fortuitous phasematching at axial interfaces and is highly sensitive to the resonant part of the third-order susceptibility. Based on phase-sensitive recordings of the vibrational spectrum of dimethyl sulfoxide in the CH3stretching range, it is shown that FE-CARS uniquely probes the spectral phase of the Raman bands of the sample. ! 2008 Elsevier B.V. All rights reserved. * Corresponding author. E-mail address: [email protected] (E.O. Potma). G Model VIBSPE-1619; No of Pages 5 Please cite this article in press as: V.V. Krishnamachari, E.O. Potma, Multi-dimensional differential imaging with FE-CARS microscopy, Vibrat. Spectrosc. (2008), doi:10.1016/j.vibspec.2008.07.009