A new millimeter- to millimeter-wave double-modulation double-resonance (MMW-MMW DM-DR) scheme has been applied to record spectra of two astronomically relevant complex organic molecules (COMs), propanal (C2H5CHO) and ethyl cyanide (C2H5CN), to demonstrate advantages of the DM-DR experimental technique. The DR technique helps to identify target transitions in a forest of lines and the implementation of a DM procedure (modulation of the pump and probe source) allows for confusion- and baseline-free spectra containing only the line(s) of interest. In particular the unambiguous assignment of weak and blended transitions in very dense MMW spectra is highlighted. Details of the observed Autler-Townes line splitting and possible future applications, such as automated analyses and adaptions of DM-DR methods to other experimental setups, are discussed.
Cite
@article{arxiv.2407.01297,
title = {Millimeter-millimeter-wave double-modulation double-resonance spectroscopy},
author = {Oliver Zingsheim and Luis Bonah and Frank Lewen and Sven Thorwirth and Holger S. P. Müller and Stephan Schlemmer},
journal= {arXiv preprint arXiv:2407.01297},
year = {2024}
}