Optical pumping enhanced double quantum nuclear spin coherences were detected in bulk GaAs and InP by two-dimensional NMR. The stimulation of the coherences was achieved using a single non-selective resonant RF pulse. This is unusual because stimulation of such coherences from a spin system at thermal equilibrium in high field would normally require a minimum of two pulses. A density matrix analysis, combined with a time-resolved study of the build-up of the double quantum coherence in GaAs, suggests that the enhancement of the double quantum coherence amplitude stems from optical pumping of dipolar nuclear spin order. (C) 2004 Elsevier B.V. All rights reserved.