Absorption and photoconductivity in GaAs and InP have been studied as functions of light intensityIup to 20 MW/cm2at 1.06 &mgr;. The two‐photon‐absorption coefficient is determined to be ≈ 0.3Icm−1forn‐GaAs and ≈ 0.2Icm−1forn‐InP. These values are much larger than that predicted by the existing theories. For then‐InP samples, the absorption by the two‐photon‐excited free carriers is found to be important, giving an absorption coefficient of ≈ 0.15I2cm−1. From the photoconductivity measurements, the concentration and the absorption cross section of holes are determined.