Titelangaben
Maiwald, Martin ; Erbert, Götz ; Klehr, Andreas ; Kronfeldt, Heinz-Detlef ; Schmidt, Heinar ; Sumpf, Bernd ; Tränkle, Günther:
Rapid shifted excitation Raman difference spectroscopy with a distributed feedback diode laser emitting at 785 nm.
In: Applied Physics B.
Bd. 85
(2006)
.
- S. 509-512.
ISSN 1432-0649
DOI: https://doi.org/10.1007/s00340-006-2459-8
Abstract
A distributed feedback (DFB) laser diode emitting at 785 nm was tested and applied as a light source for shifted excitation Raman difference spectroscopy (SERDS). Due to the physical properties of the laser diode, it was possible to shift the emission wavelength by 8 cm(-1) (0.5 nm) required for our SERDS measurements by simply changing the injection current. The internal grating ensured single mode operation at both wavelength with the frequency stability of +/- 0.06 cm(-1) (0.004 nm) required for high resolution Raman spectroscopic applications. The shifted spectra were used for calculating enhanced Raman spectra being obscured by a strong scattering background. A 16 dB (approximate to 38 fold) improvement of the signal-to-background noise (S) over bar/sigma(B) was demonstrated using blackboard chalk as a sample. The tunable DFB laser is a versatile excitation source for SERDS, which could be used in any dispersive Raman system to subtract fluorescence contributions and scattering background.