Confocal Raman microspectroscopy has previously used pinholes placed at the back focal plane of the microscope to provide depth resolution along the optical axis. The process of optimizing the pinhole alignment can often be difficult and time-consuming. We demonstrate a different approach to setting up a confocal Raman microscope using a stigmatic spectrograph and a CCD detector. This arrangement is easy to use and provides a depth resolution of ∼2 μm.
K. P. J. Williams, G. D. Pitt, D. N. Batchelder, and B. J. Kip, "Confocal Raman Microspectroscopy Using a Stigmatic Spectrograph and CCD Detector," Appl. Spectrosc. 48, 232-235 (1994)