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.