Abstract
The general theory for the effect of self‐focusing on two‐photon‐induced photolysis is developed. A chemical method of determining the self‐focusing length of liquids is described. The method is applied to the case of ruby‐laser‐induced photolysis of iodoform dissolved in toluene, m‐xylene, chlorobenzene, and chloroform. The experimental results are in complete agreement with the theoretical predictions.