Laser induced birefringence in a wavelength-mismatched cascade system of inhomogeneously broadened Yb atoms

We report the observation of laser induced birefringence (LIB) in a wavelength-mismatched cascade system (J=0 \leftrightarrow J=1 \leftrightarrow J=0 transitions) of inhomogeneously broadened ytterbium atoms with strong pump and probe fields. We investigate the transmission spectrum of two circular polarization (\sigma_p^+ and \sigma_p^-) components of strong probe field at fixed frequency, depending on the detuning of circularly polarized (\sigma_c^-) coupling field from two-photon resonance. We find that \sigma_p^+ (\sigma_p^-) polarized component exhibits a narrow electromagnetically induced absorption (transparency) spectrum. Numerical solutions of density matrix equations show qualitative agreement with experimental results. A Doppler-free dispersive LIB signal is obtained by detecting the Stokes parameter of the probe field, enabling us to stabilize the frequency of coupling laser without frequency modulation.