Transverse effects in ultrabroadband multifrequency Raman generation

The theory of ultrabroadband multifrequency Raman generation is extended, f or the first time, to allow for beam-propagation effects in one and two tra nsverse dimensions. We show that a complex transverse structure develops ev en when diffraction is neglected. Tn the general case, we examine how the u ltrabroadband multifrequency Raman generation process is affected by the in tensity, phase quality, and width of the input beams, and by the length of the Raman medium. The evolution of power spectra, intensity profiles, and g lobal characteristics of the multifrequency beams are investigated and expl ained. In the two-dimensional transverse case, bandwidths comparable to the optical carrier frequency, spanning the whole visible spectrum and beyond, are still achievable. (C) 2000 Optical Society of America [S0740-3224(00)0 1408-9] OCIS codes: 190.2620, 190.4380, 190.4410, 190.4420, 290.5910.