Tunable hybrid spectral filter and time-division multiplexing of second-order fluorescence controlled by phonon and dressing on Pr³⁺: YSO

Atom-like nonlinear responses of rare earth doped crystal Pr³⁺:Y₂SiO₅ (Pr³⁺: YSO) exhibit unique features compared with other nonlinear crystals. The responses become more interesting, while Pr³⁺: YSO is modulated simultaneously by temperature and multi-parameters related to dressed state. The generations of Stokes and fluorescence (FL) signals are demonstrated in both time and spectral domains. Here, we are presenting a new controlling strategy by interaction between dressing and phonon on Pr³⁺: YSO to manipulate the intensity of Stokes and FL signals. Interaction between dressing and phonon leads to more stable nonlinear response of the YSO crystal, which is very important for integrated quantum photonic device stability and multi-functionality. Also, we have realized tunable hybrid spectral filter (narrow-band pass notch filter (NBPNF), narrow-band stop notch filter (NBSNF)) and time-division multiplexing router on Pr³⁺: YSO by controlling the interaction between dressing and phonons. Tunable hybrid spectral filter and pure NBPNF are realized from dressing dip of Autler-Townes (AT) splitting and spectral intensity Stokes emission peak. Also, time-division multiplexing router is realized by time-domain adiabatic expansion. Furthermore, optical switch between tunable hybrid spectral filter to pure NBPNF is realized from dressing dip (AT splitting) to spectral intensity Stokes emission peak. Our experimental results suggests advanced technique for realizing tunable hybrid spectral filter with a contrast of about 98%, and optical time-division multiplexing router with channel equalization is about 85%.