Difference frequency generation in quasi‐phase‐matched LiNbO3 is carried out using a Nd:YAG laser and a high power semiconductor laser. Operation at quasi‐phase‐matching degeneracy point results in an ultrawide 0.5 μm acceptance bandwidth. Crystal‐rotation‐free wavelength tuning of 4.0–4.5 μm, with 0.2 mW output power at 4.5 μm is achieved. Separately, a tuning range 3.0–5.5 μm is demonstrated with sample rotation and a Ti:Al2O3 laser.