Superresolution of pulsed multiphoton Raman transitions - art. no. 113601

We have investigated higher order multiphoton Raman resonances with two pul sed optical frequencies. Multiphoton transfer with up to 50 photons is obse rved with milliwatts of laser power. We demonstrate that the spectral width of the multiphoton resonances can be far below the Fourier transform linew idth of the driving optical pulses. The functional dependence of the transi tion linewidth on the number of exchanged photons is found to vary with the pulse shape. Our experiment is performed with laser-cooled rubidium atoms confined in a CO2-laser optical dipole trap.