Single-Cycle 2.6 fs Pulses via Two-Stage Plasma Self-Compression

Ultrafast optics plays a pivotal role in modern science and technology, with applications ranging from fundamental research to cutting-edge technological advancements. Among the core techniques in ultrafast optics, short-pulse compression stands out for its ability to shorten pulse duration and enhance temporal resolution, thereby driving progress in optical technologies. Most methods use self-phase modulation (SPM) for spectral broadening, requiring additional compressors like grating pairs, prism pairs, or chirped mirrors to correct residual positive dispersion. However, the achievable pulse duration is limited by the bandwidth the compressor can handle. To address this, we introduce a novel post-compression approach—self-compression in plasma—that shortens pulses without requiring any subsequent dispersion engineering.