Abstract
The two-photon resonant, three-photon ionization spectrum of atomic iodine in the I* P1/22 state is presented. The I* P1/22 state is produced by photodissociation of methyl iodide, and its two-photon excitation spectrum exhibits (3 P2)np and (3 P2)nf Rydberg series converging to the I+ P23 ground state. With use of this technique, the single-photon forbidden np and nf series are readily observed to n>30.