Diagnostics of ultrashort laser pulses

We develop new schemes for diagnostics of ultrashort laser pulses. In Ref. [1], we reported a new approach for FROG reconstruction based on ptychography (a scanning coherent diffraction imaging technique). We demonstrate, numerically and experimentally, that ptychographic reconstruction works well with very partial spectrograms, e.g., spectrograms with a reduced number of measured delays and spectrograms that have been substantially spectrally filtered. You may download freely our ptychographic FROG (connection to our page Ptychographic FROG), or consider a commercial version offered by A.P.E. (connection to https://www.ape-berlin.de/en/2016/06/13/frog-meets-pulsecheck-autocorrelator/).

In Ref. [2], we proposed and demonstrated, numerically and experimentally, multiplexed FROG in which several pulses of a pulse–burst are retrieved simultaneously from a single measured trace, which corresponds to the incoherent sum of the FROG traces of the individual pulses. Implementing multiplexed FROG in GRENOUILLE (single-shot FROG) can enable characterization of pulses in non-repetitive pulse-bursts that are currently not measurable. In Ref. [3], we proposed and demonstrated, numerically and experimentally, the first deep neural network technique to reconstruct ultrashort optical pulses.

Deep learning pulse reconstruction. A deep learning network is trained to reconstruct pulses from SHG-FROG spectrograms.
  1. P. Sidorenko, O. Lahav, Z. Avnat and O. Cohen, Ptychographic reconstruction algorithm for frequency resolved optical gating: super-resolution and supreme robustness, Optica., 3, 1320 (2016)
  2. G. Ilan HahamP. Sidorenko, O. Lahav and O. Cohen, Multiplexed FROG, Optics Express, 25, 33007 (2017)
  3. T. Zahavy, A. Dikopoltsev, D. Moss, G. Ilan Haham, O. Cohen, S. Mannor and M. Segev, Deep learning reconstruction of ultrashort pulses, Optica, 5, 666 (2018)