Far-Infrared Laser Lines in 12CH3F and 13CH3F

CW and Transient Multiresonant Studies in the Near Millimeter Wave Spectrum.

“…This is the strongest lasing transition in the CH F optically pumped far infrared laser (31). Although the are -150 times smaller than in the ground state, a strong signal is still obtained with a reasonable integration time because of the large rotational absorption coefficients at these frequencies and the sensitivity of the system.…”