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Low Ripple Notch Filter Designs Using Apodized Thickness Modulation


An apodized discrete layer thickness design method for notch filters is presented. The method produces error tolerant designs with low ripple in the pass band regions without any additional numerical optimization. Sample designs are presented. Multiple approaches have been used in the past for producing notch filters (also called minus filters). The two main approaches can be grouped into ru... » read more

Ion Beam Sputtering Deposition of Fluoride Thin Films


By Aiko Ode, Veeco Instruments Thin film coatings for deep UV wavelengths are predominately produced by evaporation methods (thermal and Ebeam). Factors limiting the performance of evaporated films include surface roughness, porosity, absorption, and defect density. To enhance the films, they are typically deposited at high substrate temperatures (above 300°C.) The thermal stress created u... » read more