Direct determination of complex amplitude of arbitrary ultrashort pulses via spectral phase conjugation

• Published in: New journal of physics Vol. 23; no. 3; p. 33047
• Main Authors: Lam, Billy, Guo, Chunlei
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01-03-2021
• Subjects: Algorithms; beam characterization; Conjugation; Electric fields; Four-wave mixing; Frequency standards; Phase conjugation; Physics; polarization; Spectra; Spectrum analysis; time lens; ultrashort pulse characterization
• ISSN: 1367-2630; 1367-2630
• DOI: 10.1088/1367-2630/abee42

Unambiguous determination of the electric field of arbitrary ultrashort pulses is the key for time and frequency standards, attosecond science, and precision spectroscopy. However, a single-step technique that can simultaneously and directly characterize the spectrum, spectral phase, and the carrier-envelope phase (CEP) information of an arbitrary ultrashort pulse remains elusive. This technological roadblock hinders the current field from studying non-repeating single-shot events, since ultrashort laser pulses are often unstable. Here, we introduce a single-step reference-free technique through polarization interfering electric field with phase inverted electric field (PIE-PIE) to directly measure arbitrary ultrashort pulses in single-shot operation without using any retrieval algorithm. PIE-PIE utilizes highly efficient spectral phase conjugation based on four-wave-mixing. The ability to fully determine the spectrum, spectral phase, and CEP of relatively low intensity single-shot pulses will revolutionize ultrafast sciences and enable studies of arbitrary non-repeating ultrafast events.