Kinetic analysis of photolysis of O
3:O
2:He mixtures by UV light has been studied. Dependence of O
2(
1Δ) yield on partial pressures, flashlamp intensity, and duration was investigated. Results indicate sufficient O
2(
1Δ) yield for operation of a high-power atomic iodine laser on the I*(
2 
)

m I(
2 
) transition.