Wide Field of View Lensing Spatially Variant Photonic Crystals

OUSD (R&E) CRITICAL TECHNOLOGY AREA(S): 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: Design, fabricate, and characterize photonic crystals offering wide field-of-view lensing capabilities at short-wave and middle-wave infrared wavelengths. DESCRIPTION: Novel three-dimensional (3D) devices are sought that are based on spatially variant photonic crystals and which support energy focusing across an ultrawide field of view and operation across a wide range of the infrared spectrum. The devices must be based on a 3D photonic-crystal architecture with an embedded lensing or focusing capability. Structural features of the devices should have a size which permits practical and scalable microfabrication. The designs must support a variety of structural geometries that are not limited to canonical shapes like cubes, shells, or rods. The design process should be intuitive and easy to replicate and/or modify, therefore designs based on optimization algorithms or inverse-design are generally not desired. The designs must also include structures that are internally connected and self-supporting (i.e., no support material). The devices should be comprised of practical materials, and not exotic high-index- or negative-index materials, metal, or other media that are lossy, difficult to fabricate, or costly to procure. The successful team will use open-source tools to perform simulation, design, and analysis that explore a variety of designs and provide proof of concept. Related devices based on transformation optics, gradient index, and optimization algorithms typically fail to meet one or more of the criteria listed above. An alternative, novel approach is sought to overcome these limitations. The successful team will (1) demonstrate a novel design approach to meet the criteria, (2) perform simulations/analyses to provide a proof-of-concept for the proposed devices, and (3) fabricate functional devices operating across various infrared wavelengths. PHASE I: As this is a Direct-to-Phase-II (D2P2) topic, no Phase I awards will be made as a result of this topic. To qualify for this D2P2 topic, the Government expects the applicant(s) to demonstrate feasibility by means of a prior Phase I-type effort that does not constitute work undertaken as part of a prior or ongoing SBIR/STTR funding agreement. In the Phase I-type effort, , the applicant shall have developed open-source software tools that offer the user the capability to model the following scenarios with spatially variant photonic crystals: embedded lenses, multiplexing similar or dissimilar wavelengths, beam collimation through sharp bends with minimal energy loss, sidelobe suppression, and frequency dependent surfaces. These models should facilitate focusing and beam control over a relatively wide field of view within the SWIR and MWIR bands. Basic fabrication and characterization of such structures are highly desired. A D2P2 award is requested because of the demonstrations the sponsoring organization has observed during lab evaluations of the candidate technology. Lens-embedded spatially variant photonic crystals have been successfully demonstrated to achieve focusing over a relatively wide FOV. The entire structure comprised only a single low-index material, and the focal length and angular FOV could be tuned. Awarding a Phase 2 SBIR would allow for the development of photonic crystals with increased WFOV capabilities using appropriate materials for the SWIR and MWIR ranges. Great potential in this technology has been identified and we wish to expand its application to better fit our customers' needs. PHASE II: Awardee(s) will fabricate the most promising lens-embedded designs that are agreed upon with the topic's principal investigator and that meet the criteria of Phase 1 above. The fabricated devices will undergo inspection and electromagnetic characterization to validate a wide field of view, sufficient bandwidth, polarization insensitivity, and related performance metrics. Explore fabrication with various materials to support a wide range of the infrared spectrum. Identify applications where these devices would offer improvements in size, weight, power, complexity, and efficiency. A device operating in relevant environments is expected to be successfully demonstrated at AFRL at Eglin AFB. PHASE III DUAL USE APPLICATIONS: Energy directing devices are used for many commercial applications including aerospace, automotive, land, and remote sensing applications. Devices meeting the desired criteria, including reduced weight and complexity, would provide a considerable improvement to existing solutions and would find widespread commercial applications in these areas. REFERENCES: M. Noori, M. Soroosh and H. Baghban. "Self-collimation in photonic crystals: Applications and opportunities." Ann. Phys. 2018, 530, 1700049-1 - 1700049-21, https://onlinelibrary.wiley.com/doi/epdf/10.1002/andp.201700049. M. Li, W. Li, H. Huang, J. Wang, Y. Li, A. Wu, Z. Sheng, X. Wang, S. Zou and F. Gan. "All-Angle Quasi-Self-Collimation Effect in a Rod-Type Silicon Photonic Crystal." IEEE Photonics Journal 2015, 7(1), 1-8. B. B. Oner, M. Turduev and H. Kurt. "High-efficiency beam bending using graded photonic crystals." Opt. Lett. 2013, 38(10), 1688-1690, http://ol.osa.org/abstract.cfm?URI=ol-38-10-1688; KEYWORDS: spatially variant photonic crystals; lens embedded; wide field of view; SWIR; MWIR; low-index material