Broadband and ultrafast all‐optical switching based on transition metal carbide

Abstract Ultrafast all‐optical switches have attracted considerable attention for breaking through the speed limitation of electric devices. However, ultrafast and high‐efficiency all‐optical switches based on two‐dimensional (2D) materials can be achieved due to their strong nonlinear optical response and ultrafast carrier dynamic. For this reason, we propose the pump‐probe method to achieve an ultrafast optical switcher with a response time of 192 fs and a switching energy of 800 nJ by using transition metal carbide (Nb 2 C). The response time and switching energy are far smaller than that of the all‐optical device based on the saturable absorption effect of 2D materials. It is believed that the Nb 2 C‐based all‐optical switch provides a novel idea to achieve a high‐performance all‐optical device and has the potential for application in high‐speed photonics processing.