Metaoptic Enabled MWIR Micro Lenslet Arrays

As Infrared optical systems play an ever-increasing role in sensors, early threat warning, and consumer applications such as spatial sensing in self-driving cars and cellphones the need for a fast, efficient, and reliable test best for these systems grows more important. Infrared scene projectors (IRSP) provide this service but require updates and advancements to keep pace with the systems they are designed to test. Modern IRSPs are built of emissive arrays of LEDs, VCSELs, or other similar sources. For maximum utility, these sources are either individually addressed and modulated, or coupled to a DMD, to provide rapid and variable scene generation. In all cases, a microlens array (MLA) is relied upon to provide maximum light extraction, a high degree of uniformity, and a collimated output to easily couple into whatever optical system is being tested. This in turn provides a challenge as the fabrication of an MLA in the midwave or longwave infrared requires the use of Zinc Selenide, Zinc Sulfide, and special class chalcogenides glasses such (IR26, IG6, As40Se60). These materials are often difficult to grow, machine, mold, or polish into complicated and miniature optical surfaces, leading to significant lead times (6 – 8 months) and fraught development cycles. One way to bypass this difficulty is to leverage meta-optics, otherwise known as planar or flat optics. Metaoptics allow widespread, highly efficient, and inexpensive semiconductor fabrication technologies to be leveraged to create the small scale, precise MLAs modern IRSPs require. With proper design and manufacturing, metaoptic MLAs have the potential to out-perform traditional refractive MLAs performance, while also allowing for a significantly reduced lead time in the design, development, and fabrication cycle.This proposal aims to address the current deficiencies in design and fabrication of refractive MLA that will allow us to leverage these technologies in the IR regime. By filling this gap, we can potentially revolutionize the efficiency of both new and existing IRSPs, which in turn can act as a catalyst for the development of new and exciting IR Systems for both defense and commercial applications. A rapid, accurate, and efficient test bed will reduce development times for these products. Beyond the use in IRSPs, metaoptic MLAs have the potential to dramatically increase the sensitivity of IR sensors as well, by increasing collection efficiency and improving the effective fill factor of FPAs. The proposed methodology in this proposal will effectively augment the performance of current of IR systems from by improving both the systems themselves as well as the test beds for characterizing and improving these systems.