They started with the experimental set up traditionally used for second harmonic generation studies in Geiger's group, which included a femtosecond laser oscillator from Newport Spectra Physics, optical lenses and mirrors, and a flow cell produced in - house for housing the alpha - quartz / water interface. (pnnl.gov)
Dragomir Neshev at the Australian National University in Canberra and his colleagues have shown that the nanocrystals can emit the absorbed infrared energy within the visible spectrum — a property called second harmonic generation. (newscientist.com)
Organic molecules can also show second harmonic generation — if they contain «polar groups», such as the amino (NH2) and nitro (NO2) groups. (newscientist.com)