On-site Shifted Excitation Raman Difference Spectroscopy for Soil Investigations
Shifted excitation Raman difference spectroscopy (SERDS) is applied for on-site soil analysis. A portable SERDS sensor system is developed for in-field pilot-investigations including a dual-wavelength diode laser at 785 nm. The sensor system allows a rapid alternating operation between the two laser lines providing background-free SERDS spectra immediately after the measurement. SERDS extracts Raman signals of soil substances from disturbing background signals with a 15-fold improvement of the signal-to-background noise. The presented results demonstrate the capability of the portable SERDS sensor system for on-site soil analysis and furthermore show the potential for additional application fields such as geological investigations.
Martin Maiwald received his Diploma in 2004 and the Doctoral degree in 2009 from the Technische Universität Berlin, Germany, both in physics. His doctoral research was related to the development of diode-laser-based microsystem light sources for Raman spectroscopy. He is with the Ferdinand-Braun-Institut gGmbH, Leibniz-Institut für Höchstfrequenztechnik, Berlin and his current research area is in the field of diode lasers, non-linear optics for frequency conversion, and the development of compact diode laser modules and sensor systems for Raman spectroscopy and shifted excitation Raman difference spectroscopy. He is author of more than 90 publications and inventor and co-inventor of 6 patents in the field of diode lasers and Raman spectroscopy.