The development of dual band imager lens assembly designs through the application of new Calcium Lanthanum Sulfide (CLS) materials and by utilizing additional degrees of freedom such as a curved image plane. The goal is to advance the state of the art of dual band optics by both improving performance and reducing complexity. These performance improvements and potential for reduced system cost will help facilitate the adoption of the technology into more systems. The primary method to achieve these goals will be through the development of various design trade studies evaluating new materials (such as CLS), identifying improvements from advanced FPA developments such as a curved FPA, and evaluating the impact of new novel design forms.