We investigate theoretieally the color-locked twin noisy field_correlation effects in fifth_order nonlinear absorption and dispersion of ultrafast polarization beats in the RV type system.We demonstrate a phase_sensitive method for studying the three_photon six_wave mixing due to atomic coherence in this multi_level system.In the limit of the narrowband and tail approximation,the fifth_order nonlinear coefficients are independent of the color_locked noisy lights.In broadband FWM and SWM signals show time asymmetry due to field_correlation,and RDO effect of frequency_time domain.Moreover,the polarization presents RDO oscillation in frequency_domain.The reference signal is a two_photon non_degenerate four_wave mixing signal,which propagates in the direction a little different from the optical path of the SWM signal.This method is used for studying the phase dispersion of the fifth_order dispersion and absorption and for the optical heterodyne detection of the three_photon SWM signal.The fifth_order nonlinear response can be controlled and modified through the color_locked correlation of twin noisy fields.The method of phase sensitive detection can be used to detect the nonlinear absorption and dispersion of the three_photon SWM.