  The collective dipole mode is induced and measured in a spin-orbit (SO)
coupled degenerate Fermi gas of $^{173}$Yb atoms. Using a differential optical
Stark shift, we split the degeneracy of three hyperfine states in the ground
manifold, and independently couple consecutive spin states with the equal Raman
transitions. A relatively long-lived spin-orbit-coupled Fermi gas, readily
being realized with a narrow optical transition, allows to explore a
single-minimum dispersion where three minima of spin-1 system merge into and to
monitor collective dipole modes of fermions in the strong coupling regime. The
measured oscillation frequency of the dipole mode is compared with the
semi-classical calculation in the single-particle regime. Our work should pave
the way towards the characterization of spin-orbit-coupled fermions with large
spin $s>\frac{1}{2}$ in the strong coupling regime.
