Methodology of Cross-Band Two-Dimensional Fourier Spectroscopy
摘要
Two-dimensional Fourier transform spectroscopy (2D Fourier transform spectroscopy, 2D FTS) is a nonstationary nonlinear optical method based on the process of four-wave mixing involving a sequence of three femtosecond pulses. The technique has become widely used for obtaining information about the structure and ultrafast transformation of complex organic and inorganic compounds with characteristic molecular vibrations in the mid-infrared range, and is referred to as two-dimensional Fourier infrared spectroscopy (2D Fourier Infrared Spectroscopy, 2D FTIR). In one of the possible configurations of the 2D FTS technique, the excitation and probing of the objects under study are carried out in significantly different spectral ranges. In the present work, an experimental implementation of such a cross-band variant of two-dimensional Fourier spectroscopy is demonstrated using the example of recording the vibrational levels of a solution of the organic dye DCM in the frequency range 1430–1820 cm