Ultrashort laser pulse retrieval using single-shot VAMPIRE

Abstract

Characterizing ultrashort laser pulses is a challenging task. By now several methods are established which can be divided into interferometric methods like SPIDER (spectral phase interferometry for direct electric field reconstruction) [1] or MEFISTO (measurement of the electric field by interferometric spectral trace observation) [2] and spectrographic methods like FROG (frequencyresolved optical gating) [3] or TASC (temporal analysis of spectral components) [4].These methods lack of unique field retrievals of arbitrary electronic fields. This is a severe problem if the laser pulse is structured as for example in soliton molecules due to well separated frequency components [5].Non-self-referenced methods like XFROG or XSPIDER may be able to retrieve phase and intensity uniquely, but require a well-known reference pulse. This implies errors, which directly propagate into the results.It is rigorously proven that no ambiguities are present if the spectrogram of a blind-FROG measurement is non-centro-symmetric [6]. The VAMPIRE (very advanced method for phase and intensity retrieval of e-fields) [7], a spectrographic self-referencing cross-correlation technique, utilizes that by means of a conditioning filter. VAMPIRE is similar to the double-blind FROG method, but it has a conditioning filter and a new algorithm, which uses the spectra of the input pulses as constraints. The general idea is shown in Fig.