SBIR-STTR Award

An additive-manufacturing process will be developed for printing high-quality freeform inorganic gradient-index (GRIN) optical elements. Candidate nanocrystal materials including ZnS, ZrO, TiO2, PbSe, and rare-earth-doped metal oxides, will be synthesized and characterized. A process for inkjet-print depositing high-volume-percent loading density of binary, ternary, quaternary, etc., nanoparticle compositions will be demonstrated. A process for depositing uniform nanocomposite layersthat allows freeform GRIN elements to be fabricated, dried, and sintered with full densification and smooth surface finisheswill be developed. Gradient-index optical test structures will be fabricated and characterized. Using the measured material properties, in the Phase I option, an achromatic GRIN lens meeting the solicited requirements will be designed and a prototype will be fabricated. In Phase II, we will optimize the performance of the solicited lens, perform environmental testing, and delivery samples to the U.S. Navy for test and qualification. We will also extend the spectral range of the technology into the infrared.

Benefit:
The innovation has widespread applicability in military applications that require smaller, lighter-weight optics, including: night-vision goggles, smart munitions, weapon scopes and fire-control systems, and unmanned aerial vehicle (UAV) electro-optical sensors.

Keywords:
Alvarez Lens, Alvarez Lens, freeform optics, gradient-index optics, additive manufacturing, Nanocomposite, nanotechnology, GRIN

To address the U.S. Navy need for smaller lighter weight optics in manned and unmanned aircraft, and to speed up optic procurement, in this program, inorganic freeform gradient-index (GRIN) optics are being developed that are operational in the visible and thermal infrared spectral ranges. These optics are fabricated using inkjet-deposition-based additive-manufacturing to integrate nanocomposite feedstock (optical inks) into tailored optics with gradient refractive index and dispersive properties throughout the volume of the lens. In Phase I, glass GRIN optical feedstock was developed, as well as additive-manufacturing processes capable of realizing all-inorganic GRIN lenses. Building on this success, in Phase II, the sintering and densification of the optical inks will be improved via chemical modifications and the inkjet-print additive-manufacturing process will be developed through analysis and designed experiments, increasing the materials and process understanding to technology readiness level 4. In the Phase II option, the lens operational spectrum will be extended into the 1.5 3.14-m range through the introduction of new glass nanoparticles that are transparent to light in that range.

Benefit:
The automated on-demand solution-based material synthesis and deposition developed in this program enables rapid assessment of new material compositions and device designs, thereby shortening the time from discovery to delivery of new military capabilities. The few-days timespan for the design-build-test-analyze cycle enabled by the process and material innovations will, in turn, enable emboldened experimentation to realize revolutionary new optics and optical devices across myriad applications, from U.S. Navy applicationssuch as drones, laser weapons, and submarine periscopesto commercial applicationssuch as medical endoscopy, surgical eyewear, security cameras, and cell-phone cameras.

Keywords:
GRIN optic, additive manufacturing, inkjet, 3D printing, Optics, Infrared optic, nanotechnology, Printing