Microlenses, microlens arrays, and diffraction gratings can be made by irradiating a polyethylene substrate with a CO2 laser. These elements are meant to work with mid-infrared light (10.6-?m wavelength). The influence of some fabrication process variables in the final parameters of the elements is analyzed. Their quality was characterized by the direct measurement of their surface profiles. The ability of microlenses to focus mid-infrared light and to form infrared images is shown, and an introductory study of the gratings is given.