[en] We have made direct absorption measurements of the transition probability and collision broadening of the 1.3-μm ²P/sub 1/2/ → ²P/sub 3/2/ transition of atomic iodine. Atomic iodine was generated in heated iodine vapor, and the spectrum was obtained with a Fourier-transform spectrometer. A transition probability was measured that corresponds to a ²P/sub 1/2/ radiative lifetime of 125 msec. Broadening coefficients of 1.4, 1.7, 3.1, and 1.3 MHz/Torr at 1000 K were found for argon, oxygen, molecular iodine, and atomic iodine, respectively. The intensity of the (2, 4) forbidden electric-quadrupole line was measured and yielded the ratio of electric-quadrupole to magnetic dipole transition probability of 2.7 x 10^-3. Molecular absorption spectra of IO and SiI were seen in high-temperature spectra of a quartz cell containing and I₂/O₂ mixture