Simultaneous intermodulated optogalvanic spectroscopy and laser induced fluorescence in an erbium hollow cathode lamp

In this work we propose an experimental apparatus to investigate the isotope shift using two sub-Doppler techniques: Intermodulated Laser Induced Fluorescence and Intermodulated Optogalvanic Spectroscopy. The experimental set uses a portable hollow cathode lamp, which is an atomic source less expensive and simpler when compared to other techniques e.g. atomic beam. The method was applied to the erbium rare earth, being possible to observe the isotope shift for three transitions from the ground state: 0 -> 17,347.860 cm-1 (576.440 nm), 0 -> 17,157.307 cm-1 (582.842 nm) and 0 -> 17,073.800 cm-1 (585.695 nm). The experimental erbium data from the literature were used to perform simulations of spectra in order to compare and confirm the accuracy of our measurements.