InGaAs/AlGaAs V-groove quantum-wire (QWR) arrays were fabricated by holographic lithography and one-time metalorganic chemical vapour deposition (MOCVD) to evaluate gain-coupled distributed-feedback (GC-DFB) effects in the InGaAs/AlGaAs materials. Using a finite-element method (FEM), mode analysis of the actual cross-sectional Structure verified the modal gain of the QWR DFB structure. in which the gain was identified by a single peak at the Bragg wavelength of the grating. In addition, we observed a large gain anisotropy due to the gain/loss coupling in the DFB structure at a wavelength of 914 nm in the emission spectra from the 430 rim pitch QWR grating at room temperature.