Temporal interaction of hybrid signals in various phases of Eu 3+ : BiPO 4 through photon–phonon dressing

Laser interaction with doped crystals exhibiting photon–photon and photon–phonon coupling has been focused on recently. In pretext, here we report the spectral and temporal profile interaction of two lasers excitation through various phases of Eu 3+ : BiPO 4 crystals. We reveal that spectral-temporal profile interaction of hybrid signals (coexisting fluorescence and spontaneous four-wave mixing) are dressed by nested and cascade processes of two-photons (two-phonon). Such interaction comes from thermal phonon constructive and phase transition phonon destructive dressing. The spectral and temporal (profile) interactions are interrelated and reduced by about 2-times due to two-photon nested dressing in contrast to the interaction through the sum of each laser excitation. In contrast to a single laser, spectral (Fano)-dip interaction reduces by 2-times due to two-photon destructive dressing coupling. Moreover, thermal phonon dressing at 300 K exhibits 3-times more extensive temporal interaction than that at 77 K. The phase transition phonon dressing for a half hexagonal and half low-temperature monoclinic phase is about 1.5-times longer than that of the pure hexagonal phase of Eu 3+ : BiPO 4 . These results may help to understand the spectral-temporal relationship in the fields of nonlinear and quantum optics.