35 American Ceramic Society Bulletin, Vol. 100, No. 8 | www.ceramics.org Celebrating 100 years chemistries, endeavors to optimize param- eters for both focused ion beam-assisted APT specimen preparation and data collection are in progress.20 Especially, we foresee that by using plasma- or cryo- focused ion beam, undesirable ion-matter interactions beyond intended milling, which often induce microstructural defects, can be minimized during an APT tip preparation stage, thereby allowing APT to retain 3D data as close as that of an original specimen. Findings from the spatially improved microstructural analysis combined with enhanced optical metrology tools for GRIN characterization will not only reveal further insight into the material system’s response to laser and thermal treatments, but it will also refine the pre- dictive quantitative process–structure– property relationship, facilitating the design, fabrication, and expanded use of GRIN optical components. Acknowledgments This work was supported in part by the Defense Advanced Research Projects Agency under Air Force Research Laboratory contract FA8650- 12-C-7225 through the M-GRIN Tech Area 2 program. The authors gratefully acknowledge the role of our partners in this effort, including Theresa S. Mayer at Purdue University, Clara Rivero- Baleine at Lockheed Martin Corporation, Ilya Mingareev at Florida Institute of Technology, Carlo G. Pantano at Pennsylvania State University, Hugues Francois-Saint-Cyr at Thermo Fisher Scientific, Isabelle Martin at CAMECA Inc., Juejun Hu at Massachusetts Institute of Technology, and Martin C. Richardson at the University of Central Florida. We also recognize the significant contributions of the numerous former students and research staff who contributed to this work. About the authors Myungkoo Kang and Kathleen A. 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