Berkeley Lab Researchers Find Way to Control Light in
Densely Packed Nanowaveguides
(June 26, 2015) A new route to ultrahigh density, ultracompact integrated
photonic circuitry has been discovered by researchers with the Lawrence Berkeley National Laboratory
(Berkeley Lab) and the University of California (UC) Berkeley. The team has
developed a technique for effectively controlling pulses of light in closely
packed nanoscale waveguides, an essential requirement for high-performance
optical communications and chip-scale quantum computing.
Xiang Zhang, director of Berkeley Lab’s Materials Sciences
Division, led a study in which a mathematical concept called “adiabatic
elimination” is applied to optical nanowaveguides, the photonic versions of
electronic circuits. Through the combination of coupled systems – a standard
technique for controlling the movement of light through a pair of waveguides –
and adiabatic elimination, Zhang and his research team are able to eliminate an
inherent and vexing “crosstalk” problem for nanowaveguides that are too densely
packed.