Nanoscale optical pulse limiter facilitated by refractory metallic quantum wells

In the past several decades, physicists have conducted deep laboratory investigations into nonlinear optics, plasma physics and quantum science using advanced high-intensity, ultrashort-pulse lasers. Increased use of the technology naturally risked damaging the optical detection systems and therefore they proposed a variety of optical limiting mechanisms and devices. Device miniaturization of such designs while maintaining superior integrability and control can, however, become complex. In a new report, Haoliang Qian and a research team in electrical and computer engineering, materials science, chemistry and the Center for Memory and Recording Research at the University of California, San Diego, U.S., detailed a reflection-mode pulse limiter. They engineered the device using nanoscale refractory films made of aluminum oxide and sandwiched titanium nitride (Al2O3/TiN/Al2O3) to build the metallic quantum wells (MQWs). The quantum size effect of the MQW provided large and ultra-fast Kerr-type nonlinearities. Functional multilayers containing these MQWs will find new applications in meta-optics, nanophotonics and nonlinear optics, and the results are now published on Science Advances.