Multiphoton detachment from H- has been studied using linearly polarized light for photon energies from 0.15 to 0.39 eV. Characteristic threshold structures were observed. The electron detachment rates are estimated at peak laser intensities from 2 to 12 GW/cm2 in the laboratory frame. The two-photon detachment data reveal intensity-dependent shifts of the H- electron detachment threshold energy.
