Photon echo three-pulse

Bigot J-Y, Portella M T, Schoenlein R W, Bardeen C J, Migus A and Shank C V 1991 Non-Markovian dephasing of molecules in solution measured with three-pulse femtosecond photon echoes Phys. Rev. Lett. 66 1138 1... 

Shortly thereafter came reports of integrated three-pulse photon echoes, especially using the echo peak shift to provide information about spectral diffusion [21, 23]. In one experiment [10, 23] the peak shift shows an intriguing oscillation at short times with a period of about 180 fs, followed by a slower relaxation with a decay time of 1.4 ps. The three-pulse echo amplitude can also be heterodyned, leading to 2DIR experiments [24 26]. The latter experiments provide a wealth of information, and there are several ways to extract the desired spectral diffusion dynamics [149]. 

Photon Echo (PE) and Reverse Transient Grating (RTG) measurements of the loss of electronic coherence between the X( 2g+) and B(3FIou+) states of molecular iodine are measured by three pulse four wave mixing (FWM). Two cases are considered, relatively low pressure isolated iodine (1-2 Torr), and iodine at high pressure (>10torr) or in the presence of several hundred Torr of buffer gas. 

Spectrally resolved femtosecond two-colour three-pulse photon echoes for studies of molecular dynamics influence of pulse wavelengths and pulse sequence... 

In this paper we report the use of spectrally resolved two-colour three-pulse photon echoes to expand the information that can be obtained from time-resolved vibrational spectroscopy. The experiments allow the study of intramolecular dynamics and vibrational structure in both the ground and excited electronic states and demonstrate the potential of the technique for studying structural dynamics. 

In a two-colour three-pulse photon echo experiment we illuminate the sample with two pump pulses delayed by time ti2 and having wave vectors ki and k2 at the same wavelength followed by a probe pulse of wave vector kj delayed with respect to the second pump pulse... 

Fig. 3. Phase Locked IR Pulses Time domain interferometry. (A) Output IR pulses from two tunable OPA-DFGs in the 4-pm frequency regime. (B) Three examples of interferograms generated by these IR pulses. (C) Linear IR absorption spectrum of acetic acid overlapped with the output of two OPAs. (D) Photon echo signal from acetic acid upon t-scan. The x-axis is the delay of the translation stage and the insert is a blow-up of a small region.

Figure 18. The normalized electronic transition frequency correlation function M(t) 1= S(i)] obtained from the experimental three-pulse photon echo peak shifts and transient grating data for IR144 in ethanol (—) total W(t) ( ) ultrafast Gaussian component in M(t) ( ) oscillatory component that arises from intramolecular vibrational motion.

We are beginning to develop a detailed understanding of these methods (18,21,30,33,34,37-40,42,44,47-49), many of which are described in this book. We have recently demonstrated a series of novel nonlinear all-IR spectroscopic techniques (IR-pump-IR-probe, IR-three-pulse photon echoes, IR-dynamic hole burning, IR-2D spectroscopy), all of them utilizing intense femtosecond IR pulses, with the intention to develop new multidimensional spectroscopic tools to study the structure and the dynamics of proteins (30,31,41,42,50-53). We shall summarize in this contribution our work, its underlying principles, and its applications. 

The three-pulse experiments contain more information than two-pulse methods when the direction and timing of all three pulses is controlled. We have seen that this additional information cannot be interpreted within a Bloch picture. We will therefore outline in the following a more detailed theory, which includes spectral diffusion and which simultaneously explains the linear response (absorption spectrum) and the nonlinear response (four wave mixing, photon echo, transient grating, pump-probe) of vibrational transitions. 

In particular, the time coordinate t2 disappears in Equation (13), which emphasizes the fact that three-pulse photon echo experiments are necessary to characterize effects that are beyond the Bloch picture. 

Figure 3 (a) Time sequence of the (stimulated) three-pulse photon echo experiment. The times ti, t2, and t3 represent the time coordinates used in the response functions [Equations (7)—(12)] while r, T, and t measure the delay times with respect to the peak positions of the light pulses. For 5-shaped light pulses, both sets of times would be equivalent, (b) The so-called box configuration, (101) which allows the spatial separation of the third-order polarization generated in the —ki + k2 + kj and the +ki — k2 + k3 phase matched directions. 

A global fit was performed by applying the formalism outlined in Section III. A [Equation (7)—(12), (14)—(17)], which connects the transition frequency fluctuation correlation function (< right-hand side of Equation (20). The fit and the resulting first... 

Figure 20 The stimulated (three-pulse) photon echo signal of the amide I band of cyc/o-Mamb-Abu-Arg-Gly-Asp as function of delay time r and T (see Fig. 3) and its normalized first moment. The first moment decays with time (T) due to...

Mercer IP, Abend S, Gould IR, Klug DR. A quantum mechanical/molecular mechanical approach to solvation dynamics tested by three pulse photon echo measurements. In Elsaesser T, Fujimoto JG, Wiersma DA, Zinth W, eds. Ultrafast Phenomena, Berlin Springer-Verlag, 1998 532-534. 

Groot ML, Yu JY, Agarwal R, Norris JR, Fleming GR. Three-pulse photon echo experiments on the accessory pigment in the reaction center of Rhodobacter sphaeroides. J Phys Chem B 1998 102 5923-5931. 

Hamm P, Lim M, Hochstrasser RM. Non-Markovian dynamics of the vibrations of ions in water from femtosecond infrared three pulse photon echoes. Phys Rev Lett 1998 81 5326-5329. 

In a 2D three-pulse spectroscopy, two of the three pulses are time-coincident and differ only by their wave vector. The system thus interacts once with a single pulse and twice with a pulse pair. In the 2D photon echo technique we set t2 = 0. We consider the heterodyne signal [Equation (10)]. This... 

Multidimentional nonlinear infrared spectroscopy is used for identification of dynamic structures in liquids and conformational dynamics of molecules, peptides and, in principle, small proteins in solution (Asplund et al., 2000 and references herein). This spectroscopy incorporates the ability to control the responses of particular vibrational transitions depending on their couplings to one another. Two and three-pulse IR photon echo techniques were used to eliminate the inhomogeneous broadening in the IR spectrum. In the third-order IR echo methods, three phase-locked IR pulses with wave vectors kb k2, and k3 are focused on the sample at time intervals. The IR photon echo eventually emitted and the complex 2D IR spectrum is obtained with the use of Fourier transformation. The method was applied to the examination of vibrational properties of N-methyl acetamid and a dipeptide, acyl-proline-NH2.in D20. The 2D IR spectrum showed peaks at 1,610 and 1, 670 cm 1, the two frequencies ofthe acyl-proline dipeptide. Geometry and time-ordering of the incoming pulse sequence in fifth-order 2D spectroscopy is shown in Fig. 1.3. 

S. A. Passing, Y. Nagasawa, G. R. Fleming, Three Pulse Stimulated Photon Echo Experiments as a Probe of Polar Solvation Dynamics Utility of Harmonic Bath Modes, J. Chem. Phys. 107, 6094 (1997). 

The dephasing time, T2, can be measured by the photon echo technique or determined from the homogeneous width of saturation spectroscopy, which is a Fourier transform of the former, as easily seen from Eq. (5.35). When a sample is irradiated with three consecutive laser pulses at times, 0, t2, and f3, an echo pulse is emitted at time, t2 + t. This is called stimulated photon echo. Several additional echo techniques have been proposed. 

Figure B2.1.10 Stimulated photon-echo peak-shift (3PEPS) signals. Top pulse sequence and interpulse delays t and T. Bottom echo signals scanned as a function of delay t at three different population periods T, obtained with samples of a tetrapyrrole-containing light-harvesting protein subunit, the a subunit of C-phycocyanin.

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