Ultrafast on‐Chip Remotely‐Triggered All‐Optical Switching Based on Epsilon‐Near‐Zero Nanocomposites (Laser Photonics Rev. 11(5)/2017)

An on‐chip remotely‐triggered, ultralow‐power, ultrafast, and nanoscale all‐optical switch with high switching efficiency was realized in integrated photonic circuits. Extremely large optical nonlinearity enhancement associated with epsilon‐near‐zero multi‐component nanocomposite is achieved through dispersion engineering. Compared with previous reports of on‐chip direct‐triggered all‐optical switching, the threshold control intensity, 560 kW/cm 2 , was reduced by four orders of magnitude, while maintaining an ultrafast switching time of 15 ps. This not only paves the way for the realization of cascaded and complicated logic processing circuits and quantum solid chips, but also provides a strategy to construct photonic materials with ultrafast and large third‐order nonlinearity. (Picture: Zhen Chai et al., article number 1700042, in this issue)