Theoretical calculations are described to investigate the behavior of solid explosive when heated by
continuous and pulsed laser. A one-dimensional model is proposed and the numerical solutions have
been obtained for the time-dependent nonlinear heat equation with the appropriate initial and boundary
conditions. Relationships between various ignition parameters are analyzed and possible ignition
mechanisms are discussed. Theoretical calculations are applied to the primary solid explosive b lead
azide. It has been argued that the initiation of b lead azide with low energy laser is thermal in origin.