Femtosecond Stimulated Raman Microscopy
(Development of most modern methods in quantum optics for studies of ultra fast processes in chemistry and biology)
Raman microscopy combines the non-invasive imaging capabilities of optical microscopy with the chemical sensitivity of Raman spectroscopy. Raman micrographs allow to record
"chemical maps" of the distribution of (bio-)molecules, for instance, within a cell. In this respect, Raman microscopy is superior to other modern microscopy approaches
which usually require marker molecules that stain or label the sample. We recently developed
a new imaging technique, Femtosecond Stimulated Raman Microscopy (FSRM) featuring theses properties.
FSRM employs a femtosecond white light pulse Raman probe) and an intense picosecond pulse (Raman pump) both derived from a laser / amplifier system. The pulses are coupled into a scanning microscope. Stimulated Raman interaction impinges the Raman signature of the focal spot onto the white light spectrum. This spectrum is read-out in multi-channel fashion. By raster-scanning the sample, complete Raman spectra from each pixel are obtained and converted into chemical images. To demonstrate the feasibility of the approach Raman images of polystyrene beads dispersed in water have been recorded.
We presently work on increasing the spatial resolution and the acquisition rate of the technique. It shall then deliver chemical maps of cells.
|Previous coworkers: ||Evelyn Plötz|
|Publications: ||"A 75 MHz Light Source for Femtosecond Stimulated Raman Microscopy"|
E. Ploetz, B. Marx, T. Klein, R. Huber, P. Gilch
Optics Express: 17 (2009) 18612-18620Details
"A novel imaging system: Femtosecond Stimulated Raman Microscopy (FSRM)"
E. Ploetz, S. Laimgruber, P. Gilch
Proceed. 13th Int. Conf. on Time-resolv. Vibr. Spectr., Freising, May 19-25 (2007) 28Details
"Femtosecond stimulated Raman microscopy"
E. Ploetz, S. Laimgruber, S. Berner, W. Zinth, P. Gilch
Appl. Phys. B 87 (2007) 389Details