We report the design of a highly nonlinear holey fiber for making a mid-infrared light source at 4.36 μm. A solid-core chalcogenide-based index-guided holey microstructured optical fiber with circular air holes has been exploited to numerically demonstrate wavelength translation via four-wave mixing. We employ a thulium-doped fiber laser as the pump with a power of 5 W. Our simulations indicate that a maximum parametric gain of 20.5 dB with a bandwidth of 16 nm is achievable in this designed fiber, resulting in a power conversion efficiency of more than 17.6%. © 2013 IOP Publishing Ltd.