Two-color laser field

The harmonic generation of helium in a strong two-color laser field has also been studied [243,108]. The two lasers with frequencies cuo and 2a>o, respectively, are operated with the same peak intensity and a constant relative phase difference external potential of the form... 

Th. Mercouris, C.A. Nicolaides, Solution of the many-electron many- photon problem for strong fields Application to Lr in one- and two-color laser fields, Phys. Rev. A 67... 

Asymmetry of Above-Threshold Ionization of Metal Clusters in Two-Color Laser Fields A Time-Dependent Density-Functional Study. 

This chapter focused on the role of photon polarization in producing ultrafast Jt-electron rotation by a single-color laser. If a two-color laser is employed, its relative optical phase can be another controlling factor for the rotation direction of Jt electrons [17, 39]. The next step is to extend the series of our studies to cover ultrafast nonadiabatic dynamics of chiral aromatic molecules in laser fields of arbitrary polarization. 

Sakakibara J, Adrian RJ (1999) Whole field measurement of temperature in water using two-color laser induced fluorescence. Exp Fluids 26 7-15... 

Consider, by contrast, a two-color experiment where the continuum is accessed by two laser fields with a well defined relative phase, a and , . A schematic illustration of the experiment envisioned is provided in Fig. 1 a, where we consider the specific case of excitation with one- and three-photon fields of... 

In Section 6.3.2, we presented experimental data from strong-field excitation and ionization of K atoms with shaped femtosecond laser pulses. Here we give a description of the apparatus and strategy used in the experiments presented in this contribution. Figure 6.12 gives an overview over the complete experimental two-color setup. For the experiments on strong-field control of K atoms (cf Sections 6.3.2.2, 6.3.2.3, and 6.5) only the one-color beamline was used. An... 

Figure 10.6 Two-dimensional REMPI spectrogram of the centrifuged Oj molecules. Ion signal is color coded as a function of the frequency of the ionizing laser field, which undergoes two-photon absorption on the C Yl v = 2) X L v" = 0) transition, and molecular angular momentum, which is defined by...

In this chapter, we summarize recent progress in the photochemistry of shortlived species by use of multibeam excitation, including our recent achievements in this field. Our research group has employed various multibeam irradiation methods to reveal reaction processes of various excited intermediates, including basic molecules and biomolecules. We also achieved direct observation of shortlived species utilizing ultrashort pulse lasers. These results are interesting recent examples of reactions induced by multibeam irradiation. Based on the excitation method, this chapter is divided into the following sections Pulse Radiolysis-Laser Flash Photolysis (Section II), Two-Color Two-Laser Flash Photolysis (Section III), and Three-Color Three-Laser Flash Photolysis (Section IV). Each section is further divided into subsections based on the topics. 

A pulse laser is another excitation source for generating various reactive intermediates efficiently. In the case of pulse lasers, selective excitation of the ground and excited states is easy because laser pulses with various wavelengths can be obtained by harmonic generation with nonlinear crystals. Recent development of a laser utilizing optical parametric oscillation, which emits a variable wavelength, enlarged the scope of study. Thus, two-color two-laser flash photolysis has been adapted to a wide variety of fields [3]. Furthermore, utilization of... 

The nanosecond-picosecond two-color two-laser flash photolysis method is also useful to study the excited state of radicals, that is, the D, state. We applied nanosecond-picosecond two-color two-laser flash photolysis to detect the absorption and fluorescence spectra of the ketyl radical of benzophenone and its derivatives (BPH and BPDH ) in the excited state in the UV-visible region [111], since BPH and BPDH are well investigated radicals in various fields. Since BPH and BPDH are generated from irreversible ways, such as photoionization, we employed a streak camera to realize the single-shot detection of these intermediates. 

M. Dorr, R.M. PotvHege, D. Proulx, R. Shakeshaft, Multiphoton processes in an intense laser field. VI. Two-color ionization with incommensurable frequencies, Phys. Rev. A 44 (1991) 574. 

S.-M. Wang, S.-L. Cong, K.-J. Yuan, Y.-Y. Niu, Photoionization of NO molecule in two-color femtosecond pulse laser fields, Chem. Phys. Lett. 417 (2006) 164. 

Z. Chen,M. Shapiro, P. Brumer, Interference control of photodissociation branching ratios. Two-color frequency tuning of intense laser fields, Chem. Phys. Lett. 228 (1994) 289. 

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