Pulse stroboscopic method

The first picosecond pulse radiolysis experiment was carried out in the late 1960s by the so-called stroboscopic method (generally pomp and probe method) at University of... 

A simplified instrument for the measurement of fluorescent lifetimes using the stroboscopic method has been described by Brown (67). The major virtue of this system is that it makes use of a Tektronix oscilloscope to obtain all the necessary trigger pulses, including a trigger of continuously variable delay. Since most laboratories are equipped with a good oscilloscope, the need to purchase expensive trigger-delay apparatus is thus eliminated. 

Stroboscopic method. In this method the photomultiplier is also gated or pulsed having an on-time of nanosecond or subnanosecond duration during which it operates at very high gain. The flash lamp and the detector systems are synchronized such that a suitable delay can be introduced between the two. The gated photomultiplier samples the photocurrent each time the lamp fires and the photocurrent is thus proportional to the... 

Improvements in time resolution in the stroboscopic method were achieved at the University of Tokyo by use of a twin linac system in which one aceelerator delivers the electron pulse to the sample and the other generates the Cerenkov light pulse used as the analyzing light [151]. Both linacs are driven by the same microwave source and delay between the electron pulse and the light pulse is achieved by phase shifters [151a]. The result is that the time interval between these two pulses is less than 3 ps. 

The lifetime of the photo-induced state in a given material dictates the instruments required for the determination of its structure. The smaller is the lifetime of such a species, the more chalienging the experiment becomes. These instmmental challenges are divisible into four categories steady-state methods (t > min), pseudo-steady-state methods (ms < Tq < min), and stroboscopic methods using a pulsed X-ray source generated by means of either a mechanical chopper (/as instrumental requirements as a function of time. 

TCSPC, intensity decays were measured using stroboscopic or pulse sampling methods. The basic idea is to sample tfie intensity decay repetitively following pulsed excitation (Figure 4.25). The detection gato is dtsi aced across the intensity decay until the entire decay is measured. In fact, the first TD lifetime instruments used gated detection to sample the intensity decay. ... 

The pulse-probe technique can be extended to multiwavelength detection by using the ultrafast laser pulse to generate a white-light continuum probe, which can be dispersed with a spectrograph across a diode array or CCD detector after traversing the sample. Due to lower probe intensity, Cerenkov emission from the sample would be expected to be more of a complication in this case, but the correction methods developed for stroboscopic Cerenkov detection would also work here. 

M. Wulff, F. Schotte, G. Naylor, D. Bourgeois, K. Moffat, G. Mourou Time-resolved structures of macromolecules at the ESRF Single-pulse Laue diffraction, stroboscopic data collection and femtosecond flash photolysis. Nucl. Instrum. Methods Phys. Res. A 398, 69 (1997)... 

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