A wafer level spectrometer is provided. A sensor apparatus for measuring characteristics of optical radiation has a substrate and a low profile spectrally selective detection system located within the substrate at one or more spatially separated locations. The spectrally selective detection system includes a generally laminar array of wavelength selectors optically coupled to a corresponding array of optical detectors. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.