Plasmonic nanogap confinement extends sum frequency vibrational spectroscopy to the nanoscale, enabling direct imaging of molecular orientation at interfaces. (Nanowerk News) Sum-frequency generation ...

Periodic signal analysis enhances optics and photonics experiments using lock-in amplifiers and boxcar techniques.

An ultraviolet photon-counting dual-comb spectrometer. Two ultraviolet frequency combs of slightly different pulse repetition frequencies are generated at very low light levels by nonlinear frequency ...