  We investigate the prospects of using two-mode intensity squeezed twin-beams,
generated in Rb vapor, to improve the sensitivity of spectroscopic measurements
by engaging two-photon Raman transitions. As a proof of principle
demonstration, we demonstrated the quantum-enhanced measurements of the Rb
$5D_{3/2}$ hyperfine structure with reduced requirements for the Raman pump
laser power and Rb vapor number density.
