Abstract: An electro-optical detector array and spectrum analyzer system consisting of a novel detector array containing a plurality of photodetectors, each covered by a different narrow band optical filter and each activated when an electromagnetic energy source admitted by the narrow band optical filter is present whereby discrete components of the electromagnetic energy can be identified simultaneously and nearly instantaneously by comparison with the known wavelength admittance characteristics of said narrow band optical filter. Companion electronics and associated metering equipment complete the system.