Observation and analysis of new eletronic states of KRb using resonance enhanced two-photon ionization spectroscopy in a supersonic molecular beam

William C. Stwalley, Michael Bellos, Ryan Carollo +2 more

The high-resolution rovibronic spectroscopies of cold and ultracold molecules (e.g. supersonic molecular beam excitation spectra (MB), photoassociation spectra of ultracold atoms (PA), resonance-enhanced multiphoton ionization spectra (REMPI), stimulated Raman transfer (SRT) spectra) are of major current interest. This manuscript summarizes the significant level of understanding of these various spectroscopies, enabled by using simple graphical and semiclassical ideas and shortcuts. Physical realizations of these spectroscopies will be illustrated using the alkali metal diatomic molecules, both homonuclear (e.g. Rb2) and heteronuclear (e.g. KRb).

Jacob P. Covey

Jinpeng Yuan, Zhonghua Ji, Yanting Zhao +4 more

Resonance-enhanced two-photon ionization (RETPI) is a powerful tool in ultracold molecular photoassociation spectroscopy measurement. Using the RETPI, the line shape of ultracold RbCs molecular photoassociation spectroscopy, which contains intensity and full width at half maximum, is measured and analyzed systematically with varied photoassociation laser intensity and ionization laser energy. The saturation of photoassociation spectroscopy at a high ionization laser energy is observed and the suppression phenomenon is observed at high photoassociation laser intensity. The saturation intensity of RbCs molecular photoassociation, the linewidths of excited state molecules in different rovibrational levels at zero photoassociation laser intensity, and two-photon ionization efficiency have been derived from the line shape of photoassociation spectroscopy. The line shape analysis of photoassociation spectroscopy is important for precision spectroscopic analysis.

William C. Stwalley

William C. Stwalley

Hui Li, Zhe Shi, Jinbo Liu +4 more

Nitric oxide (NO) is cooled to 1 K in a seeded Ar supersonic molecular beam. NO molecules are ionized by one-color two-photon resonant enhanced multiphoton ionization (REMPI) process to form an ultracold plasma. The density of the ionized molecules in the illuminated volume approaches to 1.5 × 10 13 cm −3 . Prompt electrons, plasma electrons and intact NO + ions are produced during this process. Experimental results confirm that the lifetime of this ultracold plasma is longer than 18.3 μs. This is the first report of NO ultracold plasma with significant lifetime produced by one-color two-photon REMPI process.