obtaining Raman spectral data of an unknown carbon fiber from at least two different examination conditions, wherein the examination conditions include a laser irradiation focus spot location about 5 micrometers or more from an end of the unknown carbon fiber;

extracting, by a computing system comprising one or more computing devices, a plurality of parameters from the Raman spectral data of the unknown carbon fiber;

projecting, by the computing system, the Raman spectral data parameters of the unknown carbon fiber into a plurality of principal component spaces, each principal component space being associated with a single reference fiber, each principal component space comprising at least a first principal component and a second principal component of Raman spectral data of the single reference fiber associated with that principal component space, the Raman spectral data of each reference fiber having been obtained at the at least two different examination conditions; and

assigning, by the computing system, an identity to the unknown carbon fiber based upon the results of a similarity test between the projected Raman spectra data and each principal component space.