In this paper, numerical computations of the intensity spectral density function of a wave field scattered by a one‐dimensional, power law phase screen are presented. The computations verify theoretically derived asymptotic results showing that when the power law index is greater than three, the scintillation index saturates at a value larger than unity. Moreover, strong focusing, a local maximum in the scintillation index variation with increasing perturbation strength, only occurs in a one‐dimensional medium when the spectral index is greater than or equal to 3. The application of these results to the interpretation of radiowave scintillation data is discus