Apparatus for carrying out spatially offset Raman spectroscopy (SORS) is described. The apparatus comprises a rotatable prism arranged such that a spatial offset between an entry region and a collection region at a sample is dependent upon an angle of rotation of the prism.

A side surface inspection device is provided for a cylindrical battery having a side surface defining first to fourth areas. The side surface inspection device includes a first light to emit light toward the side surface of the cylindrical battery; a plurality of mirrors having a first to fourth mirrors that each reflect light emitted from the first light to be incident on each of the first to fourth areas, respectively, of the cylindrical battery, and are configured to reflect light reflected by each of the first to fourth areas, respectively, of the cylindrical battery; and a camera to receive the light reflected by each of the plurality of mirrors and configured to form an image including images of the first to fourth areas of the cylindrical battery.