A Tunable Laser Interference Lithography for Extreme Period Range Gratings

We introduce a method called period mixing for fabricating diffraction gratings with an extreme range of periods. This method uses capability of laser interference lithography to easily aggregate multiple optical fields. Period mixing principle is described to obtain relations for the interference field characterization. Incorporating motorized components into this optical system has opened new possibilities for fine period tuning, enhancing the precision and efficiency of the process. Gratings featuring different aspects of period mixing are both designed and fabricated.