The interaction of laser radiation from a Nd/glass laser with single crystals of cyclotrimethylene trinitramine (RDX) secondary explosive and RDX slices (cleaved from larger crystals of RDX) has been studied by high‐speed framing photography with microsecond interframe times. Decomposition and deflagration were recorded following ignition at localized regions or ‘‘hot spots.’’ ©1996 American Institute of Physics.