By using a proprietary modulated excitation process and dual time-base recording, BH FLIM systems are capable of recording FLIM and PLIM simultaneously. The technique is based on pixel-synchronous on-off modulation of a high-frequency pulsed excitation laser. FLIM is derived from the photon times within the laser pulse period, PLIM from the photon times within the modulation period. the technique obtains high sensitivity and high photon efficiency both for FLIM and PLIM. Different than other PLIM techniques, it does not require a reduction of the laser pulse period, and works both with one-photon and multiphoton excitation. Applications are mainly related to metabolic imaging: The FLIM data deliver the metabolic state, the PLIM data deliver the oxygen concentration. Please see figure below. Simultaneous FLIM/PLIM is available in the bh DCS-family laser scanning FLIM systems and in the bh FLIM systems for the Zeiss LSM 710/7807980 family systems. For details please see ‘ Simultaneous Phosphorescence and Fluorescence Lifetime Imaging by Multi-Dimensional TCSPC and Multi-Pulse Excitation‘.
