Flat Optic Micro Lenslet Array

OUSD (R&E) CRITICAL TECHNOLOGY AREA(S): Trusted AI and Autonomy; Integrated Sensing and Cyber The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with the Announcement. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws. OBJECTIVE: Develop a concept and demonstrate a flat optical system for use as a micro lenslet array, appropriate for use with digital micromirror (DMD) devices. DESCRIPTION: Lenslet arrays provide optical functionality that is desirable for use with arrayed devices such as digital micromirror (DMD) devices, LED arrays, and laser arrays. Standard glass/plastic lenslet arrays have undesirable limitations including wavefront errors, acceptance angle, focal length, and device pitch. Flat replacements for traditional lenslet arrays are desired with pitch and formats that can match standard DMD formats, operate in the visible spectrum, have significant working distance, have large angular acceptance, are polarization agnostic, have high transmittance, have tunable designs, and are manufacturable at scale. An added advantage (optional) would be the ability to tile lenslet arrays to make a larger format device. Extension for use in mid-wave infrared (3.0 m to 5.0 m) is also of interest. PHASE I: Concepts will be evaluated based on a variety of optical and geometrical characteristics such as: lens fill factor, minimum achievable focus spot for a lenslet, wavefront error/image quality, acceptance angle, working distance, bandwidth, uniformity across polarization states, and transmittance. Consideration is also provided for manufacturability, complexity, ability to tile arrays, and tunability to reach other bands as desired. The evaluations may be made using simulations if necessary, though preference is given to actual hardware feasibility demonstration using DMDs or representative hardware PHASE II: Refinement of the concept, development of design, fabrication, and demonstration of a prototype and prototype experimentation/testing will constitute the majority of the Phase 2 effort. Any remaining concept refinements needed after a Phase 1 completion will be addressed early in the Phase 2 effort, ideally in parallel with the design efforts. Prototype to be developed should not be specific to a single illumination type (i.e. laser, LED, or halogen). The design process should include planning for demonstration and testing/measurements. Construction and demonstration of a prototype is expected to require a substantial portion of the phase 2 program depending on lead times of components requiring procurement as well as number of iterations of fabrication to refine the process. With proper planning for demonstration and testing, the final portion of the phase 2 program should be relatively short and produce high quality data that indicates the design functions as intended. PHASE III DUAL USE APPLICATIONS: Outputs from Phase 2 are anticipated to be TRL 6 but may require additional effort to refine to a more manufacturable design. Phase 3 will concentrate on the manufacturability as well as the manufacturing process itself to prepare the vendor to commercially offer a fully operational product. A final product is expected to be demonstrated and marketed to AFRL as well as our transition partner in the 782d Test Squadron. Additional Phase 3 planning will occur during the Phase 2 process once a design is established and manufacturing requirements and manufacturability become more apparent. REFERENCES: Fan, ZB., Qiu, HY., Zhang, HL. et al. A broadband achromatic metalens array for integral imaging in the visible. Light Sci Appl 8, 67 (2019). Pisano, G., Austermann, J., Beall, J. et al. Development of Flat Silicon-Based Mesh Lens Arrays for Millimeter and Sub-millimeter Wave Astronomy. J Low Temp Phys 199, 923 934 (2020).; KEYWORDS: lenslet; metamaterials; optical array; projection; hardware-in-the-loop; test; optics