Hyperfine structure measurements in 51V using Doppler-free saturated absorption and polarization spectroscopy

Abstract

The hyperfine structure in the six fine structure levels in the 3d 44p 6F term in 51V has been studied and the magnetic dipole interaction constants were determined employing Doppler-free saturation spectroscopy on vanadium atoms produced by sputtering in a hollow-cathode discharge. The drastic improvement that can be obtained in saturated absorption spectroscopy by modulating the pump beam at a high modulation frequency is clearly demonstrated in the present paper. For these high modulation frequencies a comparison with polarization spectroscopy showed that the intrinsic advantage in signal-to-noise ration that polarization spectroscopy has at low modulation frequencies is essentially lost at higher modulation frequencies. Also, in this particular case, the effects of velocity changing collisions were rather small. Consequently the two methods were considered being equally powerful in the present measurement situation.