TIGER: TIme-Gated Electric field Reconstruction

TL;DR

TIGER is a new self-referenced method for complete, single-shot temporal characterization of ultrashort laser pulses using second-order nonlinear signals and a novel four-faced pyramid optical element.

Contribution

It introduces a novel, spectral measurement-free technique for ultrashort pulse characterization using spatially encoded time delays and nonlinear signals.

Findings

Successfully reconstructed various laser pulse shapes

Demonstrated single-shot measurement capability

Provided detailed theoretical analysis of the method

Abstract

We present a novel self-referenced method for the complete temporal characterization (phase and amplitude) of ultrashort optical laser pulses. The technique, called TIme-Gated Electric field Reconstruction (TIGER), measures a second-order nonlinear signal (namely, second harmonic generation or two-photon absorption) produced by four time-delayed replicas of the input pulse. The delays are spatially encoded in the beam profile using a four-faced pyramid-like optical element. The presented technique enables single shot measurement and does not require any spectral measurements, in contrast with well-known self-referenced characterization methods. Depending on the chosen geometry, the recorded TIGER signal can be either interferometric (i.e., carrier frequency resolved) or intensimetric. This paper describes the principle operation of the device together with a detailed theoretical analysis. TIGER measurements of various laser pulse shapes with their reconstructions are then presented demonstrating the relevance of this original approach.