The tapered quantum cascade lasers operating at about 9.0μm are reported.In contrast to the common ridge waveguide laser,tapered devices give rather small horizontal beam divergence.Performances of devices with identical 11μm ridge waveguide sections and different tapered gain sections are comparatively studied.The optimal taper angle of 3°leads to a relative high output power and a very small horizontal beam divergence of 7.1°. The tapered quantum cascade lasers operating at about 9.0 μm are reported. In contrast to the common ridge waveguide laser, tapered devices give rather small horizontal beam divergence. Performances of devices with identical 11 μm ridge waveguide sections and different tapered gain sections are comparatively studied. optimal taper angle of 3 ° leads to a relative high output power and a very small horizontal beam divergence of 7.1 °.