Advanced window coatings for drone and ground based applications

Advanced window coatings being developed for drone applications need to be multi-functional. A typical window design includes a hydrophobic outer coating, a solar filter rejecting unwanted spectrum, an EMI layer and/or heater to prevent icing and anti-reflection films. Hydrophobic and hydrophilic thin film materials are available from various vendors. We present our experience in using these materials and their comparative performance with respect to film adhesion and durability. The window can be a common aperture for several different sensors. Adding an EMI shield using a transmitting conducting oxide (TCO) is challenged when visible and NIR transmission is needed. The trade-off between required conductivity and NIR transmission is presented.