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Navy Research Lab’s Transparent Spinel Ceramic

Dept. of Defense

Photo credit: Naval Research Laboratory.

Laboratory: Naval Research Laboratory (NRL)

Technology: Transparent spinel ceramic

Opportunity: This NRL-patented technology is available for licensing to companies with commercial interest. Collaborative research and development are available under a Cooperative Research and Development Agreement (CRADA).

Details: NRL has developed a suite of processes to create transparent spinel (MgAl2O4) ceramic, which is superior to the glass, sapphire, and other materials traditionally used for applications such as high-energy laser windows and lightweight armor. Commonly used vacuum hot presses are used to sinter spinel powder into transparent solid materials. The NRL method includes a novel spray-coating process to uniformly coat the spinel powder particles with a sintering aid. As a result, the amount of sintering aid required was reduced significantly, while still allowing the end product to be sintered to full density and transparency. Additionally, the sintering process was modified to completely eliminate residual lithium fluoride (LiF) through evaporation, thereby avoiding unwanted chemical reactions. NRL’s transparent spinel ceramic can also be paired with its patented BGG glass material, which offers excellent optical transmission in the visible and mid-infrared wavelength range, and the low cost and ease of use and production offered by glass.


  • Excellent transmission in visible wavelengths and mid-wavelength infrared (0.2-5.0 microns)—superior to sapphire
  • Process scalability to large sizes and complex shapes
  • Strong, rigid, and environmentally durable
  • Reduced manufacturing cost over existing technologies—high reproducibility, high yield


  • Consumer electronics
  • High-energy lasers
  • Transparent armor

Contact: To learn more about this technology and how to license or partner with NRL, visit

View the original NRL technology listing here: