A direct-write patterning of InGaN during molecular-beam epitaxy has been achieved by using in situ focused thermal beam. The surface of growing InGaN is exposed to a 50 mu m diameter pulse laser beam that is directed to controlled locations. Indium (In) mole fraction is reduced from 0.85 where it is adjacent to laser exposure, and to 0.75 where exposure takes place, whereas it is 0.81 away from exposed regions during a nominal 78 nm deposition on a thick InGaN buffer. The effect of local heating increases surface diffusion of In without evaporating the written materials. One additional feature of direct-write patterning is the enhancement of photoluminescence efficiency, which increases by a factor of 7 compared to nonwritten regions. Gray scale features with composition variations are also demonstrated by laser direct write. (c) 2007 American Vacuum Society.