a) near-Gaussian beam quality
b) high conversion efficiency (perfect geometric / spatial overlap of the pump & signal beam)
c) robust, low magnification design
The more compact the design, the better the opto-mechanical stability as well as ability to temperature control all optics taking part in the DFG process. Our latest DFG source as well as the detection module used in our DFG spectrometer for the detection of CH2O is shown below.
The DFG source uses a two stage imaging design, which reduces the magnification and hence improves the opto-mechanical stability as well as temperature stability. (D.Richter and P Weibring, 2005)
