Turning infrared into visible light with molecular optomechanical devices

Abstract:
Frequency conversion plays an essential role in electromagnetic signal processing by allowing detection and modulation of signals that are in a frequency band where suitable technologies are not widely accessible. A prominent example is that of electromagnetic waves in the infrared range. Their detection and processing remain a technological challenge despite their great interest for molecular analysis of gases, chemicals and biological tissues.

In this seminar I will introduce an optomechanical approach, revisiting well-studied absorption and Raman scattering of molecular vibrations inside nanocavities, to the detection of infrared photons. I will then present our experimental works demonstrating (1) continuous-wave infrared to visible frequency upconversion mediated by molecular 
vibrations and (2) its control via 3D nanomechanical positioning of the scanning probe tip of a near-field optical microscope.
To conclude, I will suggest several routes for the exploration of this conversion process in intriguing physical regimes and applications both in vibrational spectroscopy and chemically selective infrared nanoimaging.