We present a detailed study of four-wave mixing in a long-wavelength distributed-feedback (DFB) laser for both nearly degenerate and nondegenerate pump-probe detunings. We characterize scaling laws of the power dependence of multiple conjugate waves on the pump and probe power levels for the nearly degenerate case. We also measure the output ratio of the probe and conjugate waves up to a detuning of 500 GHz and report the cavity enhancement of the DFB laser on this output ratio. ©1997 American Institute of Physics.