TY - JOUR

T1 - Advanced phase retrieval for dispersion scan: a comparative study

AU - Escoto, Esmerando

AU - Tajalli, Ayhan

AU - Nagy, Tamas

AU - Steinmeyer, Günter

PY - 2018/1

Y1 - 2018/1

N2 - Dispersion scan is a self-referenced measurement technique for ultrashort pulses. Similar to frequency-resolved optical gating, the dispersion scan technique records the dependence of nonlinearly generated spectra as a function of a parameter. For the two mentioned techniques, these parameters are the delay and the dispersion, respectively. While dispersion scan seems to offer a number of potential advantages over other characterization methods, in particular for measuring few-cycle pulses, retrieval of the spectral phase from the measured traces has so far mostly relied on the Nelder–Mead algorithm, which has a tendency to stagnate in a local minimum and may produce ghost satellites in the retrieval of pulses with complex spectra. We evaluate three different strategies to overcome these retrieval problems, namely, regularization, use of a generalized-projections algorithm, and an evolutionary retrieval algorithm. While all these measures are found to improve the precision and convergence of dispersion scan retrieval, differential evolution is found to provide the best performance, enabling the near-perfect retrieval of the phase of complex supercontinuum pulses, even in the presence of strong detection noise and limited phase-matching bandwidth of the nonlinear process.

AB - Dispersion scan is a self-referenced measurement technique for ultrashort pulses. Similar to frequency-resolved optical gating, the dispersion scan technique records the dependence of nonlinearly generated spectra as a function of a parameter. For the two mentioned techniques, these parameters are the delay and the dispersion, respectively. While dispersion scan seems to offer a number of potential advantages over other characterization methods, in particular for measuring few-cycle pulses, retrieval of the spectral phase from the measured traces has so far mostly relied on the Nelder–Mead algorithm, which has a tendency to stagnate in a local minimum and may produce ghost satellites in the retrieval of pulses with complex spectra. We evaluate three different strategies to overcome these retrieval problems, namely, regularization, use of a generalized-projections algorithm, and an evolutionary retrieval algorithm. While all these measures are found to improve the precision and convergence of dispersion scan retrieval, differential evolution is found to provide the best performance, enabling the near-perfect retrieval of the phase of complex supercontinuum pulses, even in the presence of strong detection noise and limited phase-matching bandwidth of the nonlinear process.

UR - http://www.scopus.com/inward/record.url?scp=85047436578&partnerID=8YFLogxK

U2 - 10.1364/JOSAB.35.000008

DO - 10.1364/JOSAB.35.000008

M3 - Article

AN - SCOPUS:85047436578

VL - 35

SP - 8

EP - 19

JO - Journal of the Optical Society of America B: Optical Physics

JF - Journal of the Optical Society of America B: Optical Physics

SN - 0740-3224

IS - 1

ER -