In this Letter, we numerically simulate the generation of a 1-15 μm mid-infrared supercontinuum (SC) from a highly nonlinear Ge 11.5 As 24 Se 64.5 -based photonic crystal fiber (PCF). This ultra-broadband SC is achieved in a 100 mm long PCF pumped using 85 fs laser pulses operated at 3.1 μm and a peak pulse power of 3 kW. The proposed design offers a flat dispersion profile with two zero dispersion wavelengths. This broad and flat dispersion profile of the Ge 11.5 As 24 Se 64.5 PCF, combined with the high nonlinearity (2474 W −1 km −1 ), generates an ultra-broadband SC.