Phase-controllable multi-laser system with coaxially combined near-infrared and subcycle mid-infrared and THz pulsed beams

With the progress of infrared high-intensity pulse technology, the ultrafast control of electronic states has been attracting considerable attention. Most elementary excitations of solids have resonance energy in the mid-infrared (MIR) frequency domain. Therefore, to understand these dynamics in detail and open up new possibilities, new technological innovations are desired. In this study, we have developed a system that combines 8 fs near-infrared pulsed light with carrier envelope phase-controllable subcycle MIR and THz pulsed lights. This technology has produced a new method that enables the analysis of phase-sensitive phenomena in the near-infrared to far-infrared region.