Simple fiber-based solution for coherent multidimensional spectroscopy in the visible regime.

We report on a setup for coherent multidimensional spectroscopy based on visible continuum generation obtained by propagating 130 fs, <600  μJ pulses centered at 800 nm in a 2.5 m long hollow-core fiber. We find that with these modest input pulse requirements, the fiber can produce a stable, high brightness continuum spanning the 520-900 nm region, moreover in a single propagation step. The fiber exhibits 80% transmission, and the continuum features excellent spatial mode quality. In addition, spectral phase measurements suggest the possibility of a significantly self-compressed output in the visible, which simplifies aspects of the 2D spectrometer. The applicability of this simple, low-requirement source for 2D spectroscopy is demonstrated by performing a control experiment on the molecular dye Nile Blue.