Reduced Cost, Enhanced Degrees of Freedom Optics

Attempts to make thermal IR imaging systems smaller and more affordable for widespread use face significant obstacles, especially in relationship to optics. While other parts of an IR system, like infrared focal plane arrays (IRFPAs), have advanced considerably in resolution, compactness, and affordability, advancements in infrared (IR) optics technologies have not kept pace. To address the need for low cost wide field of view (WFOV) optics for IR imaging sensors with reduced complexity, additively manufactured (AM) gradient index (GRIN) optics will be developed. A primary set of IR compatible nanocomposite optical materials, with specific refractive index spectra, providing a wide range of index and dispersion values, will be used to increase the degrees of freedom (DOF) of IR lenses, enabling geometric and chromatic aberrations to be compensated within the bulk of the lens. The enhanced DOF of GRIN optics, compared to those made from homogeneous index optical materials, allow for lens systems to be realized with a reduced number of lens elements. The cost reduction resulting from fewer components, combined with the lower cost of AM fabrication, reduces overall cost by more than a factor of five. The WFOV infrared optic will be designed based on the nanocomposite optical material properties. In a cyclical development, the lenses will be fabricated and characterized, and measurements will be used to refine the optical system design. The physical properties, along with environmental and reliability measurements will be obtained to qualify the materials for the application and confirm the lens properties over the wavelength and temperature range. Lenses will be fabricated using scalable AM production platform, and a WFOV infrared optical system will be assembled, characterized, and then demonstrated in an IR imaging system.