V type three-level symmetric second-order coherence theory of attosecond polarization beats

Based on the phase-conjugate polarization interference between two one-photon processes, we have studied theoretically the symmetric sum-frequency polarization beat (SFPB) of V type three-level system in attosecond scale in the case of arbitrary bandwidth or broadband linewidth laser. The homodyne detected SFPB signal is shown to be particularly sensitive to the statistical properties of the Markovian stochastic light fields with arbitrary bandwidth. We have found that the accuracy in the measurement of the energy-level sum of two excited states which are dipolar forbidden transition to each other is determined by the homogeneous linewidths of the optical transitions and exceeds the laser linewidth. A Doppler-free precision in the measurement of the energy-level sum can be achieved with an arbitrary bandwidth. The field correlation has weakly influence on the SFPB signal when the laser has a narrow bandwidth. When the laser has a broadband linewidth, the SFPB signal shows resonant-nonresonant cross correlation. As an attosecond ultrafast modulation process, SFPB can be extended intrinsically to any sum-frequency of energy-levels.