Selective enhancements in 2D Fourier transform optical spectroscopy with tailored pulse shapes.

Spectral features in two-dimensional Fourier transform optical spectroscopy were selectively enhanced using pulse shapes and sequences designed to amplify specific excited-state resonances. The enhancement was achieved by tailoring a small set of input parameters that control the amplitude and phase profiles of the excitation fields, coherently driving or suppressing selected resonances. The tailored pulse shapes were applied to enhance exciton and biexciton coherences in a semiconductor quantum well. Enhancement of selected resonances was demonstrated even in cases of spectrally overlapping features and complex many-body interactions. Modifications in the 2D spectral line shapes due to the tailored waveforms were calculated using the optical Bloch equations.