In some embodiments, the present invention provides an apparatus and process that includes control electronics that generate an electronic control signal; and a plurality of optically or electrically pumped semiconductor lasers, quantum-cascade lasers, optical parametric generators, or optical parametric oscillators, operatively coupled to the control electronics, that output an optical signal having a plurality of wavelengths, each wavelength having an output intensity that each of which is varied over time to simulate a combustion signature of a weapon. In some embodiments, the optical signal includes at least two different infrared wavelengths that are varied differently with time.