29 March 2011 Featured Image
in Nature Comm.

High Q microsphere

New advances in optical circular resonators for high sensitivity detection of small molecules at the group of Jordi Martorell. When at least 1 billion molecules are typically required to generate detectable light through an optical nonlinear process, ICFO PhD student Jorge Dominguez and collaborators were able to see second harmonic light from only 50 to 100 molecules by trapping the light in the whispering gallery modes of a high Q microsphere -low rate of energy loss compared to the stored energy.

These experiments might result in the development of technologies for detection of substances based on low volatility molecules -like some explosives like, for instance, PETN- since the nitrate groups of such molecule exhibit the necessary conjugation to generate second harmonic light.

The paper Whispering Gallery Microresonators for Second Harmonic Light Generation from a Low Number of Small Molecules was published in Nature Communications as featured article by ICFO PhD student Jorge Dominguez Juarez, Prof. Gregory Kozyreff from the Université Libre de Bruxelles, and Prof. Jordi Martorell, leader at ICFO of the organic nanostructured photovoltaics group.