Isotope Shifts of Nitrogen around 800 nm

The Doppler-limited absorption spectra of 14N and 15N atoms were measured around 800 nm using concentration modulation spectroscopy to study their isotope shifts. The nitrogen atoms were generated by discharging molecular nitrogen buffered with helium in a home-made discharge tube. The isotope shifts of four multiplets (3s4PJ→3p4DoJ, 3s4PJ→3p4PoJ, 3s2DJ→5p2DoJ, and 3p2PoJ→5s2PJ) were measured and their J-dependent specific mass shifts were observed and discussed.