a fiber - optic probe which is useful for measuring raman spectra of samples remote from the light source and detector . the probe head contains optical components which selectively remove unwanted fluorescence and raman scattering arising from the interaction between the raman excitation source radiation and the input optical fiber . the optics also filter the raman excitation source into a return optical fiber leading to a spectrometer or detector . in one embodiment , the disposition of optical components provides a compact probe geometry with parallel input and output fibers at one end and a sampling port at the other end . an encasement for the optics is also disclosed , for sealing the components against the environment , and for coupling the probe to specialized sampling attachments , such as for conducting surface enhanced raman spectroscopy .