A spectroscopy system is provided which is optimized for operation in the VUV region and capable of performing well in the DUV-NIR region. Additionally, the system incorporates an optical module which presents selectable sources and detectors optimized for use in the VUV and DUV-NIR. As well, the optical module provides common delivery and collection optics to enable measurements in both spectral regions to be collected using similar spot properties. The module also provides a means of quickly referencing measured data so as to ensure that highly repeatable results are achieved. The module further provides a controlled environment between the VUV source, sample chamber and VUV detector which acts to limit in a repeatable manner the absorption of VUV photons. The use of broad band data sets which encompass VUV wavelengths, in addition to the DUV-NIR wavelengths enables a greater variety of materials to be meaningfully characterized. Array based detection instrumentation may be exploited to permit the simultaneous collection of larger wavelength regions.