  We experimentally observed the Mollow quintuplet (MQ) in F=3/2 hyperfine
structure state of 3He atoms. The metastability-exchange collisions (MECs)
transfer the Mollow Triplet (MT) from the ground states of 3He atoms to the
metastable states, and the MQ is demonstrated by four Zeeman levels of F=3/2
hyperfine states with linearly polarized light. The similar effect also
achieves in the mixture cell of 3He and 4He.
