Investigation Of The Thermal Atomic Beam Fluorescence Spectrum Of （5s²）¹S₀-（5s5p）³P₁Transition In Strontium

In the thermal atomic beam of strontium, the fluorescence of (5s2)1S0-(5s5p)3P1transition is very weak, owing to its low relaxing rate(4.7x104/s), and the line widthof this transition is susceptible to the line broadening factors. It is hard to obtain ahigh precision and high signal-to-noise ratio(SNR) spectrum of the(5s2)1S0-(5s5p)3P1transition in strontium atom. The investigation of the spectrum ofthis transition which played an important role in strontium optical lattice clock maybe helpful to deeper its relative knowledge and application.In this paper, the investigation of the (5s2)1S0-(5s5p)3P1transition in strontiumatom fluorescence spectrum based on thermal atomic beam is reported. Firstly, thefactors affecting efficiency of fluorescence detecting is analyzed and an easy to beneglected factor is investigated in experiment in which we found that thefluorescence signal amplitude, when the laser beam closed to the edge ofapproaching the atom oven,is about double of the fluorescence signal amplitude,relative to the laser beam closed to the opposite edge. Secondly, a set of fluorescencecollector made of plano-convex lenses is designed using the zemax lens designingsoftware and it improved the fluorescence collecting efficiency with a2.1gain factor.At last, the factors of the line broadening of the fluorescence spectrum detected fromthe thermal atomic beam is analyzed theoretically, and a narrow line (only6.5MHz)(5s2)1S0-(5s5p)3P1transition in strontium atom fluorescence spectrum with a highSNR is obtained in experiment. What’s more, the experiment result is coincident tothe theoretical result, and this deeper our understanding of the line broadening of thistransition in atomic beam, providing a theoretical reference and experimentalreference to its relative application.