Detection of saturated absorption spectroscopy without crossover at high sensitivity

We present an experimental approach to detect the saturated absorption spectroscopy different from conventional scheme. Using this approach, crossovers are removed to avoid their overlap with other peaks in the spectrum and sensitivity of detection could be enhanced, so the spectrum could reflect energy structure of atoms more explicitly. On the other hand, without harmful influence from crossovers, locking range of the error signal is significantly increased and symmetry of the dispersion line shape is perfectly reserved, so reliability of frequency stabilization could be improved.