Pumping delay

FIG. 3 Solvation dynamics dependence of coumarin 314 probe molecule orientation at the air-water interface. Signals are generated with a 420 nm pump photon and probed by surface second harmonic signal with 840 nm (SH at 420), x Sx element. The normalized change in SH field is plotted vs. pump delay, r is derived from a single exponential fit to the data, (a) Pump polarization S (inplane), (b) Pump polarization P (out-of-plane). (Reprinted from Ref 24 with permission from the American Chemical Society.)... 

The following factors adversely influence the effect of AWAs in concrete and mortar mixes. Since pumping delays can be time consuming and costly, it is... 

We then set the pump delay to zero so that the NS operation can proceed with maximum efficiency. We analyze the output mode 7 by tilting the compensation crystal BB02 - this allows for the variation of the correlations with 6 to be directly observed. For state 2y, 0//) + e10 0y, 2//) in mode 7, the coincidence rate between detectors Dq and l)/> is proportional to sin2(0/2). We input state 2y, 0//) + e10 0y, 2//) into BS2 and record both the two-fold Dq Dp, and the four-fold Di D2 Da Dp coincidences with the ancilla path open. The two-fold coincidence rate reflects the initial correlations for the input entangled-photon pair, whereas the four-fold coincidence rate shows the correlations after a successful NS operation. Fig. 9 shows the observed coincidence rates (two-fold are solid triangles and four-fold are solid diamonds) at... 

To complete the experimental confirmation of the NS operation, we also verified its action on the input state ly, I //) (Eq. 10b). We prepare the input state K/n) = ly, 1 u) i from the polarization-entangled photons that was prepared as dr+) = ( ly) 1 1 )2 + l )i ly)2)/ /2- The HWP2 is set such that it does not rotate the polarization. Fig. 8 b shows the four-fold coincidences as a function of pump delay. At zero delay, the four-fold coincidences Di By D Ds are suppressed nearly to zero because of the effect at BS2 [Hong 1987]. The visibility of the fringe is about 89 4 %. 

CID still is widely used as an activation technique for tandem MS in FT-ICR in-stmments. The collision gas is admitted into the ICR cell through a pulsed valve. To avoid detrimental effects of the collision gas on the ultra-high vacuum of the ICR cell ( 10 ° mbar) the gas is admitted from a low pressure vessel ( 10 mbar) in short pulses (5-50 ms). This causes the cell pressure to rise to levels ( 10" mbar) that do not compromise the resolving power of FT-ICR in a noteworthy manner. To further reduce the interference with collision gas, a pump delay (1-5 s) can be inserted between CID and tn/z analysis. Generally, a set of such cycles is accumulated to obtain a spectmm. 

IRMPD is optionally available on most commercial FT-ICR instruments. The absence of a collision gas preserves the ultra-high vacuum and circumvents time-consuming pump delays in the sequence of an experiment. 

Fig. 1.4 Fifth-order Raman signal intensity calculation for water based on the MMBO method [30], (a) homogeneous limit, (b) inhomogeneous limit, n is the pump delay ra is the probe delay. Reprinted with permission from [30], Copyright 1994, American Chemical Society...

MD approach. ti is the pump delay, t2 the probe delay, times are in femtosecond [50], Reused with permission from [50], Copyright 2001, American Institute of Physics... 

The most recent contribution to the field of nonlinear response theory comes from Keyes, Space, and collaborators [56,57]. Their approach results in an exact classical response function written in terms of classical time correlation functions (TCF). The response takes into account the nonlinear polarizability and is used in a fully anharmonic MD simulation to simulate the fifth-order response of CS2 (see Fig. 1.14). The results are strikingly similar to those obtained by Jansen et al. as well as to the simulations, both MD and adiabatic INM, of liquid Xe (see Figs. 1.8 and 1.10). The dominant features are the ridge along the probe delay and the distinct lack of signal along the pump delay. 

Fig. 1.21 Heterodyne-detected 1 450+450x111 fifth-order Raman response of CS2 measured using the crossed-beam geometry at various relative phase settings. The probe delay (left) was measured with a sample pathlength of 100 pm, the pump delay (right) was measured with a sample pathlength of 300 pm [81], Reprinted from [81]. Copyright 2000, with permission from Elsevier...

Fig. 1.22 Heterodyne-detected -Riiiiii fifth-order Raman response of CS2 measured using the crossed-beam geometry and 100 p.m pathlength. Two phase settings are shown solid line is the in-phase signal (A0 = 0), dotted line is the in-quadrature signal (A0 = 7t/2), The signal scans are,/rom top to bottom, probe delay (T4), pump delay (T2), and diagonal scan (t2 = T4) [23], Reused with permission from [23], Copyright 2002, American Institute of Physics...

Fig. 1.26 Active feedback heterodyne-detected fifth-order Raman signal of CS2 measured by Kaufman et al. using the Dutch Cross polarization settings. The node is represented by a blade line. The delay conventions used are D = pump delay and t2 = probe delay. Sample pathlength used was 1 mm. Note the significant reduction in the signal along in comparison to Fig. 1.24 and the shift in the node along to less than 100 fs [87]. Figure courtesy of L.J. Kaufman and G.R. Fleming...

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