the present disclosure relates to a chemical vapor deposition system including a chemical vapor deposition chamber having a wafer position at which a wafer can be placed during chemical wafer deposition processing , and a source of reactive gases for providing reactive gases to the chemical vapor deposition chamber . this system also includes a coherent radiation source for directing a beam of coherent radiation toward the wafer position , and a shield positioned between the coherent radiation source and the wafer position . this shield is adapted to distribute energy from the beam of coherent radiation across the wafer when the wafer is located at the wafer position .