V type three-level symmetric second-order coherence theory of attosecond polarization beats
阿秒极化拍的V型三能级对称二阶相干理论

Based on the phase-conjugate polarization interference between two one-photon processes, we have studied theoretically the symmetric sum-frequency polarizati on 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 sig nal is shown to be particularly sensitive to the statistical properties of the M arkovian stochastic light fields with arbitrary bandwidth. We have found that th e accuracy in the measurement of the energy-level sum of two excited states whi ch are dipolar forbidden transition to each other is determined by the homogeneo us linewidths of the optical transitions and exceeds the laser linewidth. A Dopp ler-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 S FPB 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.