14.07.2020 | Sum Frequency Generation (SFG) Spectrometer with wide tuning range
Infrared spectroscopy is being used to characterize vibrational states of molecules. Nonlinear SFG spectroscopy provides additional information about molecules on surfaces or at interfaces. The observed SFG spectra show the deformation of molecular binding states from centro-symmetrical geometry. The intensity of the SFG signal is proportional to the square of the second order nonlinear susceptibility.
For measurements in a SFG spectrometer a tunable pulsed infrared laser beam (ωIR) is mixed with a visible laser beam (ωVIS) in order to generate an output signal at the sum frequency (ωSFG = ωIR + ωVIS). The SFG signal is generated in the visible spectral range. It can be measured efficiently and with good resolution with optical detectors like PMT or CCDs.
Topag offers several modifications of SFG spectrometers from the manufacturer Ekspla. The Classic variant covers a vibrational spectral range from 4300 to 1000cm-1 (2,3-10µm), the Advanced variant extends the measurement range to lower energies up to 625cm-1 (16µm). The double resonance SFG model provides tunability of the IR beam and an additional tunable VIS beam allowing higher molecular selectivity of measurements. The phase sensitive option enables the analysis of complex spectra of molecules at surfaces and their molecular orientation. The SFG microscope option enables measurements with micrometer resolution.
For more details, please visit our product page SFG Spectrometer.