1996 年 44 巻 6 号 p. 563-576
The combination of IR-UV double resonance spectroscopy and TOF mass spectrometry enables us to observe the vibrational spectrum of trace molecules or clusters with very high sensitivity and mass selectivity. The molecule in a specific energy level is monitored by REMPI (Resonance Enhance Multi-Photon Ionization) mass spectrometry. The infrared spectrum is observed as a depletion of the ion signal of the specific mass which is induced by the absorption of the infrared laser. The details of the spectroscopic technique and the recent works on the hydrogen bond interactions in the clusters are reviewed.