A solid fuel laser disintegrator for the disintegration of solid fuel particles by laser beams in an environment consisting of a gaseous substance with insufficient oxygen to support combustion, typically principally nitrogen. The disintegration of fuel particles results in the production of minute flammable particles which disperse in nitrogen forming a flammable gaseous mixture. The device provides means for controlling the ratio of nitrogen and minute flammable particles dispersed in nitrogen. Optional means are provided for controlled mixing of oxygen with the mixture of nitrogen and minute flammable particles. The device is typically used in conjunction with a molecular air separator for separating air into its component parts, oxygen and nitrogen.