Laser magnetic-resonance measurement of the 3P1-3P2 fine-structure splittings in 17O and 18O.

The 3 P 1 - 3 P 2 fine-structure splittings of 17 O and 18 O have been measured by far-infrared laser magnetic-resonance spectroscopy. The signals for 17 O were detected with a sample in its natural abundance (0.038%). The isotopic shifts from the corresponding interval in 16 O are +13.0 MHz for 17 O and +23.5 MHz for 18 O, in accord with theoretical expectations