Sensitivity enhancement by increasing the nonlinear crystal length in second-order autocorrelators for ultrashort laser pulses measurement

OPTICS COMMUNICATIONS

卷:437

Article

Jarabo, Sebastian¹  Rodriguez-Martin, Enrique²  Saldana-Diaz, Jose E.^1,3  Salgado-Remacha, Francisco J.¹ 

[1] Univ Zaragoza, Dept Fis Aplicada, Pedro Cerbuna 12, E-50009 Zaragoza, Spain

[2] Fagor Automat, Barrio San Andres 19, E-20500 Arrasate Mondragon, Spain

[3] Univ Nacl Huancavelica, Fac Ciencias & Ingn, Dept Acad Ciencias Bas, Huancavelica, Peru

关键词: Pulse measurement;    Interferometric autocorrelation;    Second-harmonic generation;    Phase matching;    Mode-locked fibre laser;   

DOI  :  10.1016/j.optcom.2019.01.005

来源: Elsevier

【 摘 要 】

A theoretical model for interferometric autocorrelation with long nonlinear crystal (input depleted) has been developed and applied to the measurement of the duration of ultrashort pulses. The phase-matching condition is assumed throughout pulse spectrum. The interferometric autocorrelation trace of a mode-locked fibre laser (20 nJ energy, 100 kW peak power, centred at 1595 nm) has been measured by employing a fibre interferometer to avoid misalignment effects and a BBO nonlinear crystal as long as 2 mm, in order to generate higher second-harmonic power. BBO crystal was used because it can keep the phase-matching condition throughout a wide spectrum around 1600 nm. By fitting the experimental measurements and computing according to the theoretical model exposed, it has been demonstrated that the autocorrelator sensitivity is clearly enhanced by increasing the nonlinear crystal length. A temporal duration of 0.18 ps has been obtained by fitting theoretical and experimental values.

【 授权许可】

Free