Are there advantages to using a pulsed IR source over a “chopper”?
A pulsed thermal IR source is a state-of-the-art solution as no moving parts in the device construction are necessary. Please note that electric pulsing is a modulation of the radiation power AND the spectral characteristics according to PLANCK’s law. It can however be used only for modulation frequencies up to a few ten Hz as the modulation depth of the thermal source goes down dramatically with increasing modulation frequency. For larger frequencies – for example 100 Hz – or for an exact radiation power modulation a mechanical chopper is recommended.
