Assignment of laser lines in optically pumped submillimeter lasers: HDCO, D2CO

Respectively, three and eight laser lines have been precisely measured and assigned in asymmetric-top molecules HDCO and D2CO. Frequency calculations of rotational transitions use parameters obtained from microwave studies. For frequency calculations of rovibrational transitions, vibrational energies derived from infrared band analysis have been also taken into account. The assignment is confirmed by infrared radio frequency double resonance experiments inside the submillimeter laser cavity.