Specifications

Fluorescence Lifetime Imaging 31
Fig. 46: Start-stop histogram and ps correlation obtained in the same measurement
Fluorescence Lifetime Imaging
The general principle of the TCSPC FLIM mode of the DPC-230 is the same as for the FIFO
Imaging mode of the bh SPC modules [2]. The DPC-230 records the photons detected in one
detector together with the synchronisation pulses from the scanner into a common time-tag
data stream. By analysing these data, the SPCM software assigns each individual photon to a
particular pixel of the scan area and to a particular time channel within this pixel, see Fig. 14,
page 11.
The basic system setup is illustrated in Fig. 47. The laser scanning microscope must either be
a multiphoton microscope (with a Ti:Sapphire laser) or a ps diode laser must be connected to
the scan head. The fluorescence light is coupled to the detector either from a non-descanned
port or a confocal output of the scan head. The single-photon pulses of the detector are fed
into CFD input 3 of the DPC module. A synchronisation signal from the laser is connected to
CFD input 4. For lasers with variable pulse period the SYNC pulses are delayed to make the
recording independent of the pulse period, see [2].
DPC-230 module
LVTTL
Inputs
Scan
head
Ti:Sa or ps diode
laser
Light
Light
Laser Scanning Microscope
PMC-100
Detector
DCC-100
Detector
Controller
Scan
Clock
Pulses
SYNC
from
Laser
Fig. 47: Basic system setup of a FLIM system