Temporal focusing based ultrafast high-resolution spectroscopy

Spectroscopy is an essential tool to explore the interaction between light and matter. With the extensive study of ultrafast phenomena, ultrafast spectrum analysis is in great demand. In view of the limited acquisition frame rate of the conventional spectroscopy, the ultrafast temporal focusing mechanism was proposed and demonstrated, and it is capable of capturing arbitrary waveform signal, with the acquisition frame rate up to 100 MHz. Moreover, several approaches have been proposed to further improve its accuracy and bandwidth, it has achieved 2-pm spectral resolution and 58-nm observation bandwidth, and the observation range has been further extended to microwave and terahertz span. Furthermore, this spectroscopy has successfully characterized ultrafast phenomena and mechanisms of devices, and has been applied to several ultrafast spectral imaging systems.