⁴⁹As previously mentioned, real GFC analyzers have a chopper wheel preceding the filter wheel to make the light beam pulse in addition to changing its spectral composition. This chopper wheel generates multiple light pulses per rotation of the filter wheel. Thus, the signal output by the detector is actually an amplitude-modulated waveform, with the “carrier” frequency being the chopper wheel’s pulsing and the slower “modulating” frequency being the filter wheel’s rotation cycle. Hopefully by now you see why I decided to omit the chopper wheel “for simplicity.”