Applying light-emitting diodes with narrowband emission features in differential spectroscopy.
LEDs are a promising new type of light source for differential optical absorption spectroscopy (DOAS). Varying differential structures in the emission spectrum of LEDs, however, display a potentially severe problem. We show that the structures, which originate from a Fabry-Pérot etalon, may be removed by tilting the emitter, which at the same time increases the radiant flux coupled into the subsequent optical system. The results of long-path DOAS measurements, where we apply our method on a blue LED for the suppression of periodic structures, are also presented.
Sihler
Holger
H
Institute of Environmental Physics, University of Heidelberg, Im Neuenheimer Feld 229,D-69120 Heidelberg, Germany. holger.sihler@iup.uni-heidelberg.de
Kern
Christoph
C
Pöhler
Denis
D
Platt
Ulrich
U