Picosecond modulation spectroscopy

Experimental studies of ions association became feasible with the advent of relaxation techniques, picosecond spectroscopy, and ESR spectroscopy. Pioneering work in this field was done by Eigen, e.g.298), who studied the association of inorganic ions in aqueous solutions. Recent development of field-modulation technique335) allows for detailed investigations of ions association in low polarity media. This technique requires very low concentrations of ions in the investigated systems - a condition met by solutions involving low polarity solvents. Its application to systems such as tetrabutyl ammonium picrate in... 

Another application of multimodule systems is in correlation spectroscopy of single molecules. If the photons detected in different detectors are recorded in different modules, the minimum correlation time is no longer limited by the dead time. By synchronising the macrotime clocks of the modules, a continuous correlation from the picosecond to the millisecond scale can be achieved, see Sect. 5.11.3, page 189. 

H. Lehmitz, W. Kattav, H. Harde, Modulated pumping in Cs with picosecond pulse trains, in Methods of Laser Spectroscopy, ed. by Y. Prior, A. Ben-Reuven, M. Rosenbluth (Plenum, New York, 1986), p. 97... 

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