A Raman image formed by plotting the ratio of the peak at 408 cm-1 to the valley at 420 cm-1. Because of the on-line AFM there is a reduction in the point spread function (PSF) with no contribution of out-of-focus light from above the sample surface. In addition, the stage allows for subpixel movements and this together with the reduction in the PSF results in resolutions of <100 nm, which is half the width of the feature shown in this line scan.