The presence of ultra-narrow inter-combination spectroscopic lines in
alkaline earth elements places them as promising candidates for optical atomic
clocks, quantum computation, and for probing fundmental physics. Doppler
cooling of these atoms is typically achieved through two subsequent stages: the
initial cooling is on the 1s0-1p1 transition followed by cooling using the
narrow-line 1s0-3p1 transition. However, due to significantly lower linewidth
of the second stage cooling transition, efficient transfer of atoms into the
second stage becomes technically challenging. The velocity distribution of the
atoms after the first stage of cooling is too broad for atoms to be captured
efficiently in the second stage cooling. As a result, the capture efficiency of
atoms into the second stage Magneto-Optical Trap is low, even if the linewidth
of the second stage cooling laser is artificially broadened.Comment: 7 pages, 3 figure