Hyperfine structure and isotope-shift investigations of atomic nitrogen by saturation spectroscopy.

Abstract

In this work we report a Doppler-free investigation of atomic nitrogen. As a laser source we used a narrow-band semiconductor diode laser emitting in the near infrared. Atomic nitrogen was produced by dissociating ${\mathrm{N}}_{2}$ molecules in a radio-frequency discharge sustained by helium as a buffer gas. Hyperfine structures and isotope shifts of the transitions 3p $^{4}$${\mathit{P}}_{1/2\mathrm{\ensuremath{-}}5/2}$--3s $^{4}$${\mathit{P}}_{1/2\mathrm{\ensuremath{-}}5/2}^{\mathit{o}}$ were investigated for the two stable isotopes $^{14}\mathrm{N}$ and $^{15}\mathrm{N}$ by using absorption-saturated laser spectroscopy.