*Georg Ockenfuss, Robert Sargent, VIAVI Solutions, Santa Rosa, CA
The patterning of optical filters to enable sensors dates back more than 50 years. Today this technology serves numerous aerospace, industrial, automotive, medical and consumer electronics applications. One driver for patterned coatings is to reduce Packaging size. This can be achieved by either integrating multiple spectral filtering functions on one substrate or to coat directly onto the active photo sensing areas of CMOS wafers. Another reason is to reduce cost of the final product by reducing the number of components, and by simplifying the assembly. In some instances, better optical performance can be expected due to the reduction of the number of interfaces. We describe the historical development of patterned optical filters, provide an overview of the process flow, production processes and the related challenges. We will discuss the following applications: Ambient light and color sensors for consumer electronics, continues glucose monitoring and multispectral sensing.