Determination of the sign of the population difference in a two-level system by frequency-modulation spectroscopy

Diabatic Valence-Hole States in the C2 Molecule: “Putting Humpty Dumpty Together Again”

“…In our implementation of H-atom fluorescence action spectroscopy detection of predissociated S 1 levels of acetylene, we discovered that one-color, resonance-enhanced (S 1 ← S 0 ), multi-photon dissociation of acetylene leads to efficient production of the C 2 C 1 Π g state. − In our analysis of the dispersed fluorescence spectra of the photofragments, we were struck by the highly unusual C -state vibration-rotation structure . In Figure a–c, the vibrational energy spacings (Δ G v + 1/2 ), rotational constants ( B v ), and centrifugal distortion constants ( D v ) are shown, respectively, as a function of the C -state vibrational quantum number, v .…”

Amplified Emissions Spectroscopy for Sensing Applications

“…Two years ago, we have demonstrated that the characteristics of the emission line can be obtained by a frequency-modulated laser, and the line feature information can be obtained rather than by the spectrometer. [67,68] In addition, with the information from the excited states as well as their related attributes, more physical theories and chemical reactions will be understood. Thus, amplified emission spectroscopy will provide an extremely promising approach and will bring new information to spectrum detection technology.…”