These are Raman spectra of ethanol taken using the IRAM system. Images were taken at multiples of 5 microns into the sample, starting from the coverslip/ethanol interface to 25 microns into the sample. As the focus goes deeper in to the sample, the effects of the coverslip (ex broad peak at the high end) become less prominent.
Exposure time was 10 seconds. Spectra was taken from a section of the image that was 10 pixels tall, corresponding to light going into a single fiber of the fiber bundle.