Rapid shifted excitation Raman difference spectroscopy with a distributed feedback diode laser emitting at 785 nm
- 301 Downloads
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 (≈38 fold) improvement of the signal-to-background noise S̄/σB 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.
KeywordsWavelength Shift Raman Line Single Mode Operation Raman Spec Optical Output Power
Unable to display preview. Download preview PDF.
- 10.H. Wenzel, A. Klehr, M. Braun, F. Bugge, G. Erbert, J. Fricke, A. Knauer, P. Ressel, B. Sumpf, M. Weyers, G. Tränkle, Proc. SPIE 5595, 110 (2004)Google Scholar
- 14.T. Murphy, In Situ Detection of Aromatic Compounds in Sea-Water using Surface-Enhanced Raman Scattering (SERS) (Verlag für Wissenschaft und Forschung, Berlin, 2001)Google Scholar