FOURIER TRANSFORM (INTERFEROMETRIC) NONLINEAR SPECTROSCOPIES

$^{1}$ G. V. Hartland and P. M. Felker. J. Phys. Chem. 91,5527 (1987). $^{2}$ P. M. Felker, B. F. Henson, T. C. Corcoran, L. L. Connell. and G. V. Hartland, Chem Phys. Lett. 142,439 (1987). $^{3}$ See, for example, M. D. Levenson, Introduction to Nonlinear Laser Spectroscopy (Academic, New York, 1982). $^{4}$ D. E. Reisner, P. H. Vaccaro. C. Kittrell, R. W. Field, J. L. Kinsey, and H,-L. Dai. J. Chem. Phys. 77, 593 (1982).Author Institution: Department of Chemistry and Biochemistry, University of CaliforniaResults that demonstrate interferometric $versions^{1,2}$ of coherent Raman $spectroscopy^{3}$ and slimulated emission pumping $spectroscopy^{4}$ are presented. The achievement of high spectral resolution in nonlinear spectroscopies can place stringent demands on laser light sources. When spectral resolution in a nonlinear spectroscopic experiment depends on excitation source bandwidths, one must have the capability of producing narrow bandwidth light with sufficient intensity to drive the nonlinear process of interest. This can lead to significant complexity in performing an experiment. Nonlinear interferometric techniques, analogs to linear interferometric methods such as Fourier transform infrared absorption spectroscopy, obviate the need for narrow bandwidth excitation light in high resolution experiments. Thus, the techniques allow the use of relatively easy.to.use. ``broad-band'', high power lasers in such experiments. This talk will encompass the following: (I) an outline of the principles of nonlinear interferometric techniques, (2) a presentation of experimental results on jet-cooled and gaseous samples that show the high resolution capabilities of such techniques, and (3) a discussion of the advantageous features of the interferoniernc methods